A well written and well set out book, plenty of in depth explainations of the exercises, and lots of accompanying pictures to ensure that form is correct. There are loads of exercises to keep things from going stale, plus progressions/regressions depending on ability.
I especially liked and learned from the fitness psychology section - a lot of interesting stuff in there.
The nutrition section was far from comprehensive, but to be honest it would take another book to cover all aspects of that (try Nutrition for Athletes by Anita Bean), so what was there was useful.
If you're wanting to try for the marines, or any forces, this is a great place to start.
Highly recommended.