This build for Teemo is mostly based on attackspeed.
cuz, i like Teemo that way the best :)

Items:
Vampiric scepterto start with for longer lane duration.
second I buy the berserker greavesfor attack and movement speed.
After that I buy the malady because it is quite a good item.
Then i buy the phantom dancers because they give great movement and attackspeed. The next item is for me the guinsoo's rageblade because of its stack effect and attack power bonus.
Then I buy a bloodthirster because of the lifesteal.
And at the end i buy a mandred's bloodrazorbecause of attackspeed bonus.Theblack cleaver and the frozen mallet
are also very good items.

summonerspells:
exhaust gives you and opportunity to escape and you can prevent the enemy from escaping.
heal can give you longer lane duration and can help you in a pinch.
Other good spells are:
flashfor escaping and chasing
cleance for escaping and chasing
ghost also for escaping and chasing

I did not chose ignite because you have poison to finish the job.

I hope my build is useful.
But just enjoy the game anyway.