Hey guys its Nasus, welcome to my first guide! I'm not super experienced with writing walls of text, so I'll try my best to give a simple, yet detailed guide on Trundle. =)

About Me

Y'know that guy (this could be you or a friend) who does really well almost every game, even if he loses it? Well I'm sort of like that, I tend to lose a lot of games due to various reasons, and yet most of my games I do pretty well. And I'm not talking about having the least deaths of the team, I'm actually talking about getting pretty good K/D ratios as well as towers (WHICH IS MORE IMPORTANT COUGH COUGH*). I've been level 30 for some time now and have played with all kinds of people, in normal games. I actually just played my first ranked game last night in solo queue and won 10-1 so I hope to do that more often in the future.

Trundle!

So I'm sure you've all played with/against a Trundle at some time in your LoL career. And I'm also sure that 50% of you made your conclusion about Trundle after your first interaction with him. Well regardless of how you feel about him, I am publishing this guide in order to do a few things:

Shed some light on as to how trundle works in a team.
Help veteran Trundle players expand their horizons and look at different possibilities.
Teach younglings who want to start using Trundle on how to effectively use him.

If I don't do these things to your liking, leave a comment on how I can improve this guide!

*DISCLAIMER*

I DO NOT PLAY TRUNDLE IN RANKED GAMES, HOWEVER I HAVE PLAYED HIM ENOUGH TIMES AND HAVE GOTTEN GOOD ENOUGH RESULTS TO BE ABLE TO PASS ON MY KNOWLEDGE TO OTHERS. DO NOT ASSUME I AM STONEWALL008 BECAUSE I'M NOT.

Trundle is a Hybrid DPS/Off-Tank with some pretty decent CC to help him and his team engage enemies. It is possible to build him either like a Glass Cannon, a Tanky Slugger, or a Stonewall (hehe, get it?)
Ok finally time for some Pros/Cons.

PROS

Can jungle very well
Deceptively bulky and therefore hard to kill
People tend not to target him which allows you to bash people into a pulp
DECEPTIVELY POWERFUL, especially against AD champs. 1 Q could change the tide of a 1v1 towards your favor.
Amazing ganking abilities
Great at moving around the map
Great movement in lanes

PROS

Early game is somewhat hard
Not as effective against AP teams (but not useless)
Without blue buff mana CAN become a problem
"The melee champ blues" (having to close in on your enemy, solved with W & E)
If not built properly, damage output can be terrible

There's not much to include here that hasn't been mentioned in the cheat sheet, so I'll just justify my selections as well as suggest alternatives.

Masteries

I go 0/21/9 in all 3 builds, simply because we need to make sure Trundle is as tanky as possible in early game. If you'd like, you can run 21/0/9 or 21/9/0 for Glass Cannon, however because your Rabid Bite gives you an attack boost I suggest sticking with defensive masteries.

Runes

greater mark of desolation I use this on all three builds to further boost his damage ever so slightly.
This works on all three but I only use it on Glass Cannon because I prefer to lane with it.
These are nice on the Tanky Slugger and Stonewall builds because it adds to a stat that we're focusing on. It's also helpful for jungling, so it is possible to use these on Glass Cannon.
Only use these on Glass Cannon, because we want to be able to spam Rabid Bite as well as Agony.
Trundle will need the Magic Resist, especially early game where these are much more useful.
The health boost is nice on all three builds, so don't change these.

You can also use on Glass Cannon in order to make your Madred's Bloodrazor more effective.

Summoner Spells

Ghost: Staple for Trundle, works amazingly well with Contaminate.
Ignite: Great synergy with Agony and can lead to a few early/mid game deaths. Also used to counter healing.
Teleport: You'll notice this is on Stonewall because I believe tanks should be able to get to areas quicker than anyone else, especially if your just clearing large mob waves.

Alternatives

Smite: Essential for jungling, although my builds are focused around laning Trundles.
Flash: Pretty useful for movement (which is key for Trundle's success). If used properly, you can get around your Pillar of Filth and lock your enemy down.
Heal: Useful for beginner junglers, but not needed.
Cleanse: With Mercury Treads and Contaminate, CC shouldn't be a problem, but this is still an option.
Exhaust: It's an option, useful for ganking and for shutting down champs. However I personally prefer Ignite.

Everything else is pretty much useless, but you can still try them out if you'd like.

Glass Cannon

For laning, I find the combination of stats are very nice, but I realize that some people hate using Doran's items. Instead, you can use and 5 .

Very nice synergy with Contaminate and the Magic Resist is very useful. These can be substituted for if the other team are mostly auto-attackers, or if you are doing well.

The main ingredient of this build. With this, you dish out tons of damage to any champion, including those who have little health.

Now I know what you're thinking, what about ? The thing about it is that even though you can farm like a combine, you won't be able to do enough damage to dominate throughout the ENTIRE game, not just in early/late game.

Start with . This item has everything you need, health, damage, attack speed, a slow, and movement speed. Get it.

Lifesteal will become very useful late game, especially when they start to realize that you are a threat and will start focusing you. This will keep you alive much longer.

This is more-or-less a situational item, but I stick with this to further my attack speed and damage.

At this point you can sell your and get one of the following items:

if there's ton of CC
for heavy AP
for a nice slow and AD protection
for AD auto-attackers

You can go for a damage item, however a bit of tankiness is somewhat required for late game.

Tanky Slugger and Stonewall explanations coming soon!

Even with the cheat sheet, that should be more than enough to get started with Trundle. I hope you like this guide and would highly appreciate comments/likes/dislikes. =)

More to be added soon!