I would keep the anime and manga. I wouldn't be able to throw that away. You know, there are girls that like anime too. Don't bring the busty stuff. Tell an anime-girl you want to watch "Fruits Basket".

First, if you wear glasses, get contacts. Some people look good in glasses, most people don't. Also, pick a sport and stick with it. The extra time out in fresh air will earn bonus points with girls- nothing turns a girl OFF like the smell of a guy who spent 3 days in his dorm room.

That's all I can think of.