Try checking out
Robot Books
It's a website that sells little robot toys for kids and books that range from beginner, to all type of advanced ones and also have electrical and mechanical books. If you're thinking about making a robot on your own, chek out the hobby books (
Hobby Books ) . If that doesn't work, just go to Barnes and Noble or Borders and look around for a book that you like. But for stepper motors...I don't really like them...too complicated...i like the regular motors, good old red and black wire, but then again, stepper motors go for precision and are at times expensive, I'm actually selling some that I took out of my old HP printer and another HP scanner, only because I got new better ones.