Build Guide by
Not Updated For Current Season
Not going to write a ton here, but this build gives a LOT of on-hit effects, which synergizes well with Teemo's fast attack speed.
This build is best suited for soloing mid, but you can lane anywhere really.
The last 3 items are personal preference. If you need damage, go with Infinity Edge. If the other team has casters, Wit's End is a great choice. If you really like lane jumping and getting in on the ganks, you might prefer Phantom Dancer.
Obviously if the other side has lots of mages or CC abusers, Mercury Treads can be substituted for the Berserker's Greaves.
As with any Teemo build, drop your mushroom traps at key chokepoints and on the inside track of lane corners, where other players are most likely to run into them, as well as right in front of your turrets for defensive purposes. You can also drop one as you're running away, then turn and fight once you've led your victim across happy mushroom land.
One last thing...starting out, don't be afraid to buy Doran's Sword and Doran's Shield. They give AMAZING stats for the money, I usually start with one of them. You can sell them later without taking much of a loss at all.
Good luck, and may the nubs feed you well!