I got this book as a present for a friend when he asked for a muscle-building book that had exercises that didn't require equipment. I got this book and ended up reading it before giving it to him.
If you're interested in becoming more fit and healthy, this is a good book. He covers daily stretching and deep breathing, basic nutrition (and even gives a safe, balanced, non-starvation weight-loss diet), and gives a series of exercises that can be performed whenever you have extra time throughout the day. Most of these exercises require no equipment though he also gives a few that can be done with common objects (like chairs).
The guide pictures for the exercises seem clear enough, though I only tried a few of them. Overall, I'd say this book presents an accurate, balanced few of how anyone--a skinny girl, whimpy boy, or body-building adults--can build functional muscling and become fit.