for runes i like to farm so i got 9 pen marks, 9 mana regen seals, and 9 ability glyphs. this gives your poison trail a little more damage which harrasses enemy champions and is awesome for first blood. for quints there are a couple options. i bought EXP runes and i love them. there are times when i out level everyone in the game because of the runes and farming galore. some people overly gank which ya can get you fed but if you get underleveled and the other team keeps getting out of your ganks you are going to screw your team over late game so i suggest ganking when the opportunity presents itself but get back to farming it will aid you a lot once you get a couple items. i suggest farming till level 12-14 then do a couple ganks but whenever there minions are on your side of the map go and push that lane. this defends your base and helps damage there base. i also like movement speed because of your slow/throw someone flashes away its easy to catch up and throw them back to your team.

At start singed is squishy, and his main source of damage is his poison trail and you do not have enough ability to rely on it so during laning poison as many creeps as possible but try and stay away from enemy champs until you get some items. Start out with your poison trail, the reason being is your throw takes a lot of mana and may end you back to your tower before your ready. some people say to start out with throw because it might help you land first blood, this is true but your poison might do the same. some people stay in fights in your poison trail until there almost dead then use a summoner ability to get out but the problem is there doted with your poison so they still die which in tern gives you first blood. for the first item's i like to get 1 mana pot and a regen health penet. later i come back and turn the penet into a philophers stone which pays for itself fairly quick. i try to stay in the lane until i can get my +1 boots and my philophers stone but if you need to get back to the base and heal then pick it up while your there. i am a huge fan of the +3 boots on singed because your job is to keep there squishies in the front line for your team to demolish. TF sitting back out of range run up and throw him to your team. but this is not the only purpose of throw. lets say they have a warwick that comes and ulties someone on your team throw him ASAP it will break his ult and he will be in range of your team to demolish. the +3 boots allows your to get there fast and chase down the squishies.
while your leveling be sure to have your poison trail to lvl 5 when you hit level 9 and your throw at level 2. mega adhesive is an awesome ability so get it at level 3. the reason you want it at level 3 is if the other team is being pushy throw them in the tower and slow them which will hopefully give you an early kill.

for my third item i go back for catylist then i turn catylist into Rod of ages. this item is essential it gives you more damage/farming ability and a lot of health. remember your passive your mana turns into HP so this item is awesome. for your 4th item get banshees vail or frozen heart. if there doing a lot of AD get frozen heart is 99 armor good cool down reduction and you get mana which = health. then if there doing a lot of ability get banshees vail. lots of health from the health/mana and one of the best passive's in the game. this will give you 5 items and you are actually tanky and will have almost 4k HP. for your next item you will get all the CC you will need. buy a rylies. rylies gives you ability for more damage, health and now your poison trail slows people so in team fights there low life people cant get away as easily and lets say you are loosing the fight start running back to your base and they follow in your poison trail it slows them and does damage, ive had people chase me all the way from there base to my base and 3-4 of them die because i have my poison trail up and it is eating them. next you need to look at the other team and what they are doing. Do you need to be more tanky? if yes are they doing AD? AP? or both? if there doing AD a thornmail is nice and gives you an upper hand in the fight. if its AP a force of nature gives you a lot of health regen, good MR and movement speed. if there doing both get a banshees vail, good armor, devent MR, and a passive everyone hates. if you are plenty tanky perhaps you need to do more damage, a deathcap will tear there team apart with your poison trail, and your throws will hurt.a
also, remember to always ult when team fight starts it gives you more resists, more attack speed, and more movement speed.

Items>> philophesers stone>> +3 boots>> Rod of Ages>> banshees vail or frozen heart>> frozen Heart or rylies>> Rylies>> thornmail/force of nature/deathcap

if the other team is Solid AD
phil stone>>+3 boots>> Rod Of Ages>> frozen Heart>> thornmail>>rylies>>deathcap

if they are solid AP

Phil Stone>> +3 boots >> Rod of Ages >> banshees vail>> Rylies>> Force of Nature>> Deathcap

i run into a lot of teams that just dont think when selecting characters and wind up Solid AD or solid AP not all the time but some times so i decided to include those minor adjustments in case you run into one of these teams.