No experience with the book, but you know what? It likely contains nothing that you can't learn from the internet for free. Dieting isn't complicated, but it can be if you make it that way. And you can rearrange basic diet info. into a nifty "6 week plan" but in the end, it's still the basics -- eat less, exercise more. The rest is just details.
I know that's not very helpful so I'll add some detail. Figure out what you eat on a daily basis. Then, you can really see what you're putting into your body. Next, get rid of the junk (if you eat junk). This alone might help. Next step, reduce your calories slightly, and start doing some cardio exercise. Calories in vs. calories out. The pounds will start to drop. Oh yeah, and don't forget to keep lifting heavy throughout to send signals to your body to hold onto its muscle.