Need a book on simple, effective robotics? This is the one! Written by Solarbotics' founder Dave Hrynkiw with contributions by Mark Tilden
Absolute Beginners Guide to Building Robots By Gareth Branwyn. Get the parts for the project robots too!
Intermediate Robot Building by David Cook covers all aspects of robot building, from mechanical, to electronics, to microcontroller selection
Written by Massimo Banzi (the co-founder of the Arduino Project), this nice little handbook walks you through the open-source hardware/software project that is Arduino!