If you're a fan of the TV show, you'll be intrigued by the premise of this book and want to dive into the secrets of what makes Patrick Jane so awesome. Unfortunately for you, this book won't open the doors for you that you're hoping for. This book serves mostly as a primer, giving you basic information for particular things he does, without giving you any real meat to make it happen for yourself. If you have no experience in mentalism effects or hypnosis, then this is a way for you to sound informed at a party. However, putting any of these in practice will be hard.
To the book's credit, it does reference particular episodes to explain what the author is talking about. That does make it relevant to the show. And it's not that thick, so you'll be able to knock this out in just a few hours.
Really want to amaze folks? There are several books that would give you enough information to be effective, though you would need to read each for a particular area. The Encyclopedia of Cold Reading (all you would need to prove yourself a mind reader), Anneman's Mental Miracles (to show off a little), and a basic hypnosis book (if you're willing to put in the practice time) would be more beneficial if you are truly interested in "how to be a mentalist". If you're just interested in a little more depth on what they do in the show, pick this up.