I just passed the Wireless# test today with a really good score. Before taking the test, I read every page of this book. It also has very good questions (with answers explained) at the end of each chapter. If you have a desire to work in the wireless field, but have no real experience yet, the chapters on wireless security, installation, troubleshooting and optimization really give you a head start towards that experience!
Sure you can find a study guide that will just barely give you enough information to pass the test. If you would rather have more information behind the meat, this book is for you. Some of this material was new to me, so I wanted to really know the subjects before taking the test. Besides, this book is the official study guide for the Wireless# test by the CWNP program.
This book (and certification) really is a mile wide and a couple of inches deep. Great place to start in the wireless field. After that, you're really set to start with your CWNA study and test. Now you're getting into a subject that is only a half mile wide, and many more feet deep. CWSP is even smaller but much deeper.
Good luck and have fun!