okay so this is my first build guide on the champion i love playing the most and the way i like to play him. Remember this is how i play him so you may not agree with some things so suck it up and don't downvote just because you do something differently.
Also if you think i should change some things then please comment and let me know.
Please do not downvote without
1. Trying the build yourself first and
2. without a comment saying why you downvoted it so that i can fix the build for everyomne else
Marks - magic penetration - these are for extra damage on his blind, ult and most importantly his poison.
Seals - mana regen - teemo needs this for his early game harass so that he can shoot his blind more often to annoy the **** out of his lane oposition.
Glyphs - AP per level - these are a necessity for teemo's early game as the doran's shield won't provide him any ap for his abilities to scale off of early on. but even if you would rather start with an amplyfing tome or doran's ring these are still handy for that extra damage
Quints - movement speed - i grab these so that putting points into W arent as important or necessary and so that W + ghost = no one is gonna catch you :P
You could also go for flat health quints for greater surviveability early game which i would recomend to someone just trying him for the first time
The masteries are pretty self explanatory just make sure you use the magic damage/ ability power masteries along with the much needed defensive masteries which allow temmo a little extra survivabilty early game without which would leave him far too squishy.
first item i get is the doran's shield. This is because it gives teemo more health and armour for survivability allowing you to play a little more risky then if you got doran's ring or an amplyfying tome first as they both leave you really squishy but with a bigger punch with your abilities.
From here i find you really need a mejais this is because as ap teemo it is easy to gain stacks through assists and once you know where to put the shrooms and which champs you should blind over others you'll find stacks through assists + kills will come so much easier.
after the mejais you will need boots and the obvious choice here is sorceror's shoes as there isnt many abiliteis that run have a large cd and your most important ability is the poison which is constant anyway.
The next item is specifically for your poison which is the malady adding extra damage meaning easier kills when your poison gets procked.
next item is the deathcap for a massive increase in damage especialy if there are plenty of stacks on the majais.
Then fromm here if the enemy is made up of mostly AD champs then grab zhonya's hourglass.
If the enemy is made up mostly of AP champs then grab an abyssal scepter or if they have roughly an even amount grab the rylais
that will be 6 items so then you can sell your doran's shield and grab a rylais if you havent already or just increase your ap even more by grabbing another deathcap or increase your survivabilty with a guardian angel
I use ghost and exhaust
ghost because when used with W and go into the bush where your mushy('s) are you will get away 9/10 times
I use exhaust because this allows you to take on an auto attacker AD champ no worries just blind then once blind runs out exhaust followed by blind again (if it lasts that long)
You could also use flash or ignite depemding on what summoner spells you like
I use these because i find them extremely reliable for my playstyle
Skill Sequence/ Early Game Harass
With Teemo everyone will either say you should start off with poison or you should start off with blinding dart.
I find blinding dart better. Why? because it offers a large amount of damage with one attack so when an opponent comes within range of your blinding dart hit him with it. everytime he comes withong range hit then back off this way if he chases he chases into your minions meaning they get hit more then you do. or if they dont chase you just landed alot of damage on them without taking any which is always good as they will be forced to either let you farm in piece or get hit with damage everytime they get within range meaning they will have to recall sooner and you level up a bit faster then they do either way is good.
But in saying that once you have blindind shot your poison becomes more important. It then comes into you shoukd blind them then hit them with one auto attack then get the hell back behind your minions. so thats pretty much the early game harass as teemo.
from there prioritise your poison and grab one point in your W so when you need to run you can pop it.
Pros / Cons
[*] good nuke with Q
[*] Ult does ALOT of damage and becomes quite the annoyance
[*] poison can really hurt the enemy as they try and run from you - or if they try to take you plus another team mate on at the same time as if they kill you the poison should allow your team mate to pick up the kill
[*] really good early game harass
[*] quick getaways with W + ghost
[*] not that good of sustain in fights - needs to exit/ re enter fights all the time or needs to run to the cover of his shrooms or die
[*] really squishy and spell vamp isnt that effective (might be but i've never tried it on teemo so if someone has let me know) :P
[*] tends to get focused in team fights so best to play kind of an ***ain role
I will add more when i think of it/come to it let me know if i should add more stuff or if there are things i missed.
Thanks and remember this is my first guide :)