If you're searching for some exciting NXT projects and ideas--or would simply like to build JohnNXT, a replica of the famous Johnny 5 robot--you will enjoy Daniele Benedettelli's book Creating Cool MINDSTORMS NXT Robots. The book presents helpful ideas that you can use in your own inventions and carefully integrates them in a variety of robots with detailed building instructions. In fact, these very features are why I've given the book five stars: challenging robot projects, excellent discussions of useful concepts and ideas, and exceptional building instructions.
Most of the robots seem intended for more advanced users looking for a challenge; in other words, these are generally more complex robots. For example, there are several walking robots--including three bipeds (two-legged robots), one of the most difficult types of robots to create. And with the exception of the massive, multi-NXT robot "JohnNXT" (chapter 8) and a remote control (chapter 9), you can build all the robots from the parts in a single retail LEGO MINDSTORMS NXT set. All the programming in the book is done in NXC (Not eXactly C), an unofficial text-based language with a C-like syntax.
Along the way you'll find in-depth explanations of robotics concepts and helpful descriptions of the robots. Besides an entire "theory chapter" on building biped robots (chapter 1) and another such chapter on finite state machines (chapter 3), the robot chapters themselves include explanations of concepts such as hysteresis, writing a multitask program, and quadruped (four-legged) walking as well as information on the robots' functionality and history. The author also does a good job of presenting and explaining the programming. Although prior NXC experience is helpful, such experience is not required.
The BIs (building instructions) are outstanding, which is important since they are a major part of the book. The author used advanced BI techniques, including complete electrical cables and callouts, and Ldglite to render the images, creating BIs that are remarkably "LEGO-like." I found that the BIs were generally very easy to follow even though many of the steps were complex. Such clarity is invaluable for a book that is filled with building instructions.
I admit that I didn't build the famed JohnNXT robot. Why? For starters, I don't have all the necessary pieces! All the same, I'm glad to see that the author included the robot because a number of readers will want tackle this enormous project.
In conclusion, this book is ideal for you if you're a more experienced NXT user looking to broaden your robotic horizons--while having lots of fun. Nevertheless, even if you're new to the NXT set, you would still enjoy the book. Either way, after working through the projects and grasping the concepts, you should be well-equipped to create your very own cool NXT robots.