No incredibly specific information but general ideas. As I play with teemo more and more
I will continue to improve this guide.

Runes

Attack speed and movement speed work well here. Ability power is a decent choice too just
to squeeze all you can out of your poison

Masteries

These can go however you want. At the moment, I am using alot in defense since teemo is so squishy. The improved Boost CD is REALLY helpful.

Spells

Boost and Heal are my current picks. Teemo can get away from almost ANYTHING with quick feet and a well timed boost. Heal can be subbed for clairvoyance if need be. Clairvoyance + Vision wards = Knowing where to leave your traps.

Item Build

Oh god the phantom dancer is so good. It should probably be your first major item. That or that purple sword ( can't remember name) That buffs attack speed. Late game it is really fun to just buy alot of composite/compound bows and let the darts really fly!

Skill Build

This is where teemo really shines. His build is very adaptive. I almost ALWAYS take toxic shot (the passive) when it is available since the stronger your pokes, the more effective your harass. If there is another range in your lane, you will want to take a blinding shot early. Move quick is usually not necessary for a long period of time if you buy Boots of Speed pretty early on (I recomend this). ake move quick sooner if you find yourself being chased alot. TAKE TRAP ANYTIME YOU CAN.

General Play

Teemo is about harassment, trap spam and vision spam.

Early game

While fighting over creeps in the early game, make a point of two things.

1) Having a lane partner that can punish people easily. Warwick and Carthis work well here.

2) Poking you opponent with a regular attack at any opportunity that wont result in death or a large punish. Make a point of poking them. This is very very important. You need to poke to keep their health from regening much and your poison will ensure this. For instances, If you keep poking a melee hero like jax, he will slowly be getting worked down. Eventually, you will overextend or he will decide to do something about it. He will jump strike you. This is when you blind him to protect yourself and when your lane partner punishes the jax for jumping in. Lets say you had sion with you (another good partner). Sion shoots a stun at the jax and you and he now attack him down and he dies. The jax won't have much HP due to your continuous poison pokes. A normal range harass is not as effective as teemos as they don't prevent regen and they don't put out as much damage overall. If your opponent isn't quite as impatient as the jax player was, they will simply be forced to retreat and hang back alot for fear of dying to poison. This allows for easy pushes.

Mid game

TRAP SPAMMING TIME

Basically, you should be laying traps so often that your body developes a natural rhythm for laying them. Lay them at any place you are pushing all through the jungle to keep ganekrs slow as the come for you. Litter the best hiding bushes with piles of traps to deny ambushers. If you deny an ambusher with heavy trap damage, he will be forced to retreat and will probably not make it back to ambush in time. You should also be spamming vision wards in places that are often dark, like the mouthes of your opponents base. This will help you see exactly how your opponents are pushing. Traps can also be used to kill groups of creeps, especially when they really ball up those caster creeps.
Of course, traps also make great escapes possible. Littering your favorite paths in the woods can let you run through the freely while your opponents chasing you eat big damage. You could also use the traps to set up sneaky ganks.
For example, the bushes at the river heads (the T shaped ones) have 2-3 people stand behind these bushes and fill the bush with a few traps to ensure they will catch one. Run out and fire a few shots, ending in a blinding shot, into an enemy and make a break for the bushes. Many players will see an easy kill and chase you in. Then they get slowed from your traps and your team ambushes. Thank you teemo.

Late Game

Eventually, your traps will stop killing people and will be more useful for slowing people down. At this point, you should be investing alot in your crit rate and attack speed. A teemo with 80% crits and 2.8 attack speed is terrifying. With all his MS, he can DPS just about anything down, even while retreating. He flat out crushes melee at this point with his blinding shot too.

If you have any questions or suggestions for Teemo play, post them here. Working together, we can build a really stellar quide.