I agree - take a look at the story hours forums here - there's some great stuff. The rogues gallery has some interesting things: Blackdirges thread (and front page articles) are particularly interesting.
In the way of books, if you can find a copy I'd suggest The Munchkins Guide to Power Gaming by Steve Jackson... it's style is quite over the top, but has some sound advice hidden away in there. The focus is on curbing powergamers, but in doing so has some good ideas for challenging characters.