Do not bother to learn your poison darts ability unless there's nothing else to learn since it just makes it harder to secure minion kills. With the extra mobility, you shouldn't have much trouble avoiding their harass. I use AS quints and marks and MR glyphs and armor seals both scaling runes. The attack speed really comes in handy and is more value than damage for your rune slot because you will stick to them like glue due to your passive movement speed bonus ability so your extra attack speed isn't wasted. Then you build AD items because AD items are strong right now. Personally, I like Duskblade on him. Sure, it's not amazing on its own, but let your team burst someone down first... if you're busy farming or setting up your traps somewhere and your allies manage to chase some enemies in your direction it can come in handy. Essentially you play him like Sivir, only instead of blocking a spell from the annoying support, you block heavy damage from the annoying marksman.
Oh yeah, and the mastery page...I like Fervor of Battle since he has lots of mobility to take advantage of it. Runic Armor is pretty good, too.
About the traps, I would assume it's basic knowledge but you put them in your lane behind both minion waves to make it painful for anyone to jump you or your support. With traps put down any jungle or mid that comes to get you will have a problem. You can also put them at the river to catch them off guard. They move slowly which means you don't need to activate your sprint for a while. What makes Teemo relaxing as a champ is that you don't have to mash buttons to succeed with him like you would have to do for some champs.