This is my first CISSP training book. Before purchasing one, I scanned online commentaries for suggestions. This book consistently came on top of the list. And I am happy with it thus far.
It is written clearly and concisely. Concepts are explained so that even non-technical users can grasp the subject. Shon Harris provides hints as to which areas are very important to focus on, as well which areas are useful to know, but are not likely to be covered on the exam. At the end of each chapter there is a summary list of important points as well as questions and answers to test your knowledge.