This book will not teach you how to hack, I don't think that was the intention of the author either. What this book does is teach you the lifecycle of Professional Penetration Tests and I feel it does that quite well.
The first part of the book covers ethics, careers, setting up a lab, pen test methodologies, metrics and management. This is a large part of the book and will be useful to anyone looking to get in to penetration testing as a career, there is a lot more to it than rooting boxes...
The second part covers the different phases of a penetration test: information gathering, vulnerability identification and verification, penetration and privilege escalation, maintaining access and covering your tracks.
The third part which is only 70 pages covers: reporting, archiving, cleaning up and planning for the next pen test.
The book is 500 pages which is not a lot of space to cover such a huge subject so what you get here is more of an introduction to professional penetration testing than anything else, the tools on the included DVD are good fun to practice your skills with too.
In short, if you are just getting started or are interested in becoming a penetration tester, this book should provide a lot of insight in to how a penetration test is carried out. It covers a whole lot and will give you a good understanding of the lifecycle from the Penetration Testers perspective.