Singed I believe is one of the best pure tank champions available. Early game, his fling will earn you many kills and/or assist if done right, mid game, you'll be a huge asset in team fights, and late game, you'll be running around with your team sucking up damage and absolutely raping everyone in team fights and also catching anyone who tries to escape.

Really This guide isn't so much about item builds but how to play Singed. Of course, this item build is also really awesome and I'll explain it later

Note: I'm not a top player, but I do consider myself very good with Singed, I'm only lv 29, but I commonly play with my lv 30 friends of high elo with like 500+ wins and I can usually rape even then

This guide's really long and extensive because I feel like a guide should be something that not only teaches a build, but how to use a champion as well, so there are going to be very in depth paragraphs later on

I'm not really that big of a fan of runes, they're expensive and I don't like to buy them, but if you really want to use them, all I advise is that you use runs to help your early game. Primarily, you want runes for speed and a bit of mana regen at early levels. A singed with no mana is useless, you can't fling, you can't poison, and mid-late game, you won't have any of those problems. Speed is so you can fling people early on, early flings are just extremely devastating and having speed quints will get you those flings. Singed for the first 5-10 minutes isn't that strong and so he needs a lot of help early on.

Not much to say here, all that you need to know is that ghost is ESSENTIAL
I use flash cuz I'm a flash addict and I just think it's amazingly good, but other viable spells are
Ignite
Exhaust
Teleport <--This is the best choice if you want to replace flash, Singed is extremely beneficial in team fights not only because he's a tank, but also because he can fling, I just don't use teleport cuz I'm a flash addict and use it on practically every champion

Poison Trail is going to be your main damage output, but you really need to know when and where to use it
Times you need to use it
-When you have engaged in a fight, go ahead and turn it on
-When you're running, turn it on
^Don't forget that, in fact, run in a zig zag pattern if you can so that the poison will cover more area
Early game - you can't rely on it for much, I guess you can use it to push the lane harder or score some last hits, but don't count on it actually making a difference in your opponents life, it's just not all that powerful. Be sure not to spam it early on because really it won't help that much, and also it's mana costly. You will facepalm when you try to fling someone and realize that all your mana's been spent on poison hitting for nothing. Don't overestimate this early on. Harassing with this may or may not be good, it really depends on who you're against, don't even consider trying to harass a kiter like Ashe with this, you'll facepalm really hard. After you fling, make sure that you use your Mega Adhesive and run in front of them and try to get as many ticks of poison trail as you can. Staying in front of an enemy not only will make your poison trail really effective, it may also allow you to net another fling when the cd is done

Mid game - yeah when it gets to around level 3-4 you can go ahead and farm with it, how? run back and forth through minion waves, it kills really quickly and will push a minion wave very well

Late game - it'll just farm minion waves in like seconds, turn it on really whenever you feel like cuz you'll have so much mana and regen and it's just really awesome, you can even use it for damage since most people are too dumb to avoid it

Although many people already know, standing at a place with your poison trail active WILL poison all targets in a small AOE, every time I see a Singed player simply running around dragon with poison trail I facepalm

Max this first for more farm and damage

Mega Adhesive
It's really just such a powerful slow if done right, did I mention that you have to use it right?
Yes it's very important to note that there is a delay when Singed I guess shoots it out. Luckily, it has a very nice aeo and it's range is pretty wide, it's just that if you're going to throw this down, make sure you can hit it or else it'll be a waste. But really it's just such a good slow if you can land it, and remember to always use it after you have flung someone. If you're really good, you can know where you're going fling, set a Mega Adhesive there, and when you fling them onto it, it'll give them no chance to escape.

Fling
This is Singed's most notable skill, but like all his other skills, you have to know how to use it right. It's really dumb when Singed players try to just tap E and click a champion, hoping that he'll catch and fling them. Thus, the point is to fling at unexpected times and at reasonable times. Here's some good times to fling
-When someone tries to chase you, you turn around and go for fling
-When you see that you're close enough to reach an enemy champion quickly, throw down your Mega Adhesive and fling
-Pretend to farm, run past a minion wave and then instead of retreating, fling
-Master Yi is attacking your Teemo and he's too stupid to blind him and run! Oh no! Fling that mother effer off of him
-Need to initiate? Turn on Insanity Potion and run for their squishy and fling
-Team fight has started, protect your carry! Fling people off of them! Or fling people TO your carry
Times when you shouldn't fling
-Tanks, really? Why would you even consider flinging them? That's pointless, if it's a teamfight, you're doing exactly what the would want you to do, of course, in a 2 v 1 or whatever, feel free to fling if you're sure it wont detriment your team
-One day, I was really ******ed and blind, and my Ashe was running from a Tryn with his ultimate ready, so I tried to be awesome and heroic, and tried to fling Tryn off (this is a good idea), but i realized my positioning would fling him towards Ashe, needless to say, I gave him a huge boost, he got the kill, and tower couldn't rape him since he had his ultimate. The point is, don't fling people towards the wrong kinds of people. Don't fling a Master Yi towards your Ashe, fling an Ashe towards your Master Yi
-Don't fling for dps <-- This is really dumb, fo' real, I mean it's such a great utility, but it's CD is fairly long. It's like using Sanguine Pool as Vlad for dps, it's better used some other way

Insanity Potion
Not too much to say, just use this skill whenever it seems like it's needed, honestly you can kinda spam it. Popping ghost and Insanity Potion will let you catch anyone with Fling or let you run from any fight.
Good times to use it
-Beginning of teamfights, go ahead and pop it if you think it's needed, if they blow all their CC on you, you wont really be affected since it gives really good tenacity
-Catching someone, if this isn't enough, use ghost, I guarantee you you'll be able to catch 90% of the champions
-Transportation, you can use this skill a lot, even when it doesn't seem 100% needed, if you see a good time to gank a lane, go ahead and use this to run faster if they need help
Bad times to use it
-When you don't really need it, don't use it. Yeah, it's spam-able and all but really using Insanity Potion to run back to lane is just kinda dumb...

Starting with the mana crystal will give you decent HP and it's needed for catalyst. I usually B when I can get catalyst, and if you're doing well, keep farming for boots. After you get boots and a catalyst, you reach the moment where you're somewhat tanky already since keep in mind that Empowered Bulwark will give you a LOT of HP, so past catalyst is the time where you can play more aggressively. Later turn this catalyst into a Rod of Ages. Once again, the mana from Rod of Ages will give you lots of HP thanks to Empowered Bulwark. And then turn the boots into merc treads for nice CC reduction. After this, build your rylais for obvious reasons, and then everything after that can be pretty much substituted.
Are they AP heavy? Force of Nature
Are they AD heavy? Randuin's Omen
Your team not doing so well? Banshees veil
Everything going fine? Sunfire Aegis <--This is really a personal preference, go ahead and swap this for something else if you want, I just love seeing people on fire.

Explanation for Rylais
I guess it's stupid to have slow when you WANT people to chase you. I'm level 29 and not very high normal elo, and people are dumb enough to chase Singed, but I imagine that in higher elo people are gonna be smart enough to avoid the poison trail. I mean Rylais is really flexible of an item. Rylais combo'd with your Mega Adhesive will pretty much snare them, and I like that idea a lot. If rylai's isn't your cup of tea, go ahead and skip it, it won't make too much of a difference, instead of rylais, maybe invest in a abyssal scepter.

Pro's and Con's of this build
Pro's
->You can suck up A LOT of CC and get away with it since you'll have boots AND Insanity Potion to reduce the durations
->You'll have lots and lots of health so you can absorb lots of damage
->Your slow will be really strong and you'll practically be able to catch anyone if you throw down a good Mega Adhesive

Con's
->You won't do much damage, you won't have that much AP but whatever, even if you did have a lot of AP, you shouldn't damage cuz' Singed should be used for his Fling and tankiness. Plus, it's not like Poison Trail has a good AP ratio, so even if you did have lots of AP, you won't do much damage. What's that? Fling has a 1:1 ratio? Cool! Aww... It has quite a long cooldown and isn't spam-able, also, you shouldnt even be using it much (explained later)
->You're not as fast since you don't have boots of swiftness. That's fine really, a small price to pay since you have such a strong slow and having merc treads will give you awesome CC reduction when combo'd with your Insanity Potion. Plus, when you need to catch someone just use insanity potion and ghost
->You won't have THAT much armor or Magic resist, it's alright, you've got tons of health

Sucky elo/duo lane
Since my elo sucks, I'm usually duo laning, in this case, try to lane with someone who has good CC, if there arn't any, go with a carry partner, having Singed as a partner while you're a carry will absolutely screw your opponents over. In a case like this, you can be rather aggressive and fling more. If your partner is taking a bunch of last hits, you can use a couple flings to get some CS. The faster Singed gets Rod of Ages the better he will do

solo lane
Singed should only solo lane if he's against another solo laner, and by solo, I mean top.

Early game
Duo lane: Look for any chance that your opponents overextended and can't be easily saved by his partner and fling their ***, make sure your partner knows when you're going to do so though, if you fling and partner does nothing, then you're going to facepalm
Solo: Look for any overextentions, and simply farm/last hit, there's not much singed can do early on since his damage output isn't all that great and fling won't do much early
Important: Always try to fling them to your tower, if they're dumb enough to get tower aggro, they're toast, you can even bait them close to tower and fling

Mid game
Duo and solo: There's really not much to say, you're a lot stronger now, you can fling+poison for some harass, just don't overextend or do something ******ed and you'll be fine
Important: Farm like crazy here

Late game
duo and solo: Farm as much as you can when you're not raping team fights. Try to take place in all team fights as well because Singed in a team fight will help a tremendous amount
Important: Be a participant of all team fights

Team Fights
Singed can't initiate as well as say Blitzcrank or something, but he is really great once it has started, once the fight has commited, pop Insanity Potion and run for their squishy, fling dat ***** and watch him get screwed. Of course don't forget to constantly keep poison on. After the fights over, if you have enough health, try to catch all the runners, use your Ghost and try to land that Mega Adhesive, once you get close fling dat *****, and watch your team score that ace.

Important: This is why you don't use fling for dps. When Nunu starts to use Absolute Zero what are you going to do? Fling dat *****! Kat shumpo's in and uses Death Lotus? Fling dat *****! Remember, your fling is very good at stopping channels so save it for when it's really needed! Also, it's nice to have it after a fight to fling any runners. Even if you realize you've lost a teamfight and people are chasing down your guys, fling those *****es! (Well the one with the most chance of killing your team, you might die getting in position to fling them, but you're the tank, it's kinda your job to die for the team.

Let's face it sometimes we suck. Maybe it's because it's a bad lane partner who won't do **** after you used your Fling or maybe it's cuz you're up against someone like Ashe and you can't touch them, or maybe even it's cuz you just suck that day. Either ways, when yous tart getting screwed, all you have to do is keep in mind that
->you can call for a lane switch
->you need to play more defensively and ask for ganks
->you need to change your item build
I want to talk about changing the item build, I usually don't get screwed but if you really are against someone who's denying like crazy, just go get a Heart of Gold
Are they really AD reliant? Chain mail
Are they AP reliant? Negatron Cloak

Important: Basically, you just want to get armor or magic resist against the right people and heart of gold for well... gold, if you're being denied, that is.

Singed is just an awesome champion overall and really if you want to use him all you have to keep in mind is to play smart. This guide wasn't as much to show you item builds as to help you learn how to use Singed.

What I want everyone to keep in mind is that you shouldn't always follow guides, when I judge whether someone is good at League of Legends or not, one of the things I take into account is whether they know what to do given a certain circumstance, and that's what half the game is about. Knowing what to do. Play aggressively if you think you've got a good partner or your opponents suck against you, play defensively if they've got a good jungler, build armor if their dps is too strong, and the list goes on. How you play Singed really depends on the champions around you, and the more you practice, the better you'll play when you're given a specific circumstance.

All my friends at school for making me play this game obviously
EvilDice for giving me amazing ideas and pretty much inspiring me to play Singed in the first place
Dyrus since he's such an awesome Singed player, and probably the funniest player in League of Legends (Watch any of his jax videos on solomid.net, you'll laugh your *** off)
That really awesome Singed player who whooped me and made me want to try Singed, I forgot your name sorry

Leave comments and suggestions please! It'd mean a lot to me ^^