Some may wounder, why I play Kennen on ad, but if you think a bit about it, it makes sense :D
Your W gives you 80% additional attak damage to every 5. attak, you can spamm stuns and you can follow enemies easily with the E skill.
The ultimate even allows you to win 1vs2 or to escape big fights.
Well some still say, that Kennen doesn't use his full potencial in this way, that might be right, but an Ad Kennen is absolutly a test worth :D
It's quiet fun.

Well typical atk speed, armor and penetration...
Atk speed to get your W as fast as possible ready, Armor to have more defense and Penetration to penetrate the armor xD

Seems kind of wierd for ad, but you need at least a bit ap penetration :)
It's good to get carried in the beginning by your Ap and then pwn them from lvl 6+ with your ad :)

Jeah follow these item guide and you will have success.
Hextech for its slowing effect and the hybrid stats :D

You could also use exhaust or sprint...^^

This guide is not finished, ill add informations soon