A New book is soon to be released:
The Unofficial LEGO® MINDSTORMS® NXT 2.0 Inventor's Guide helps you to harness the capabilities of the NXT set and effectively plan, build, and program NXT 2.0 robots. After a brief introduction to the pieces in the NXT set, author David J. Perdue offers practical building techniques, like how to build sturdy structures and work with gears. Perdue then teaches you how to program with the official NXT-G programming language, using both its basic and advanced functions. The second half of the book contains step-by-step instructions for building, programming, and testing a variety of sample robots (all of which can be built using only the parts found in one NXT 2.0 set). This revised edition of the bestselling book on the NXT kit has been completely updated to cover the changes in NXT 2.0.
Many of the robots are designed and the BI are made by Laurens Valk.
You can download a chapter here and it is available for pre-order.