Remember this is a build strictly for 3v3. I have tried countless builds, but this surpasses them all. This is my 1st guide so all comments both good and bad would be greatly appreciated.

Greater Mark of Strength helps you hit that few extra damage that really helps alot.
Greater Seal of Evasion gives you great survivability.
Greater Glyph/Quintessence of Alacrity give you the extra atk speed you dont get from items.

Doran's Blade - boots of speed - malady - vampiric scepter - madreds razors - Most instances get ninja tabi if they have high AP I get mercury Treads - Madreds Blood Razors - hextech gunblade If Ad Wamogs armor - Thornmail If AP banshees veil - guardian angel 2 tanks or 1 fed Black Cleaver - guardian angel

Alot of people like to go high AP with Teemo, but it for the most part only helps your Shrooms, but when your playing a good team they will get Oracle's and only make them good wards in bushes. Your on hit poison effect doesen't stack it just prolongs the effect, so you rarely get the full poison effect except for when you're harrassing.

I prefer ignite and exhaust I really believe take what u feel most comfortable with. Truthfully flash and ghost are the only other 2 spells worth getting.

I feel this gives u the best ability to support your team and still be plenty strong to 1v1 champs. There are very few champs who will give u trouble assuming the other team isn't fed. Remember you are still very squishy, but with dodge and your late game items you last much longer. Try this build a few times if your having trouble early you might need to rethink how your playing rather it be diving or being lured or maybe this build isn't just for you. I have had tremendous success with this build. Will add more to guide once I have seen some comments and answer them.