This book is useful primarily because of its handy size. You can take it anywhere - an internet café or a library, for example - where you might want to do some CSS and it provides a handy quick reference.
The early part of the book covers basic rules and there is an index at the back. In between, starting a third of the way down page 33 and ending on page 120, you'll find all the selectors with their pattern, a brief description and brief examples. The information is presented in a clear and easy-to-understand manner but you certainly couldn't use this as a training guide. You might spot one or two unfamiliar things that look as if they could be useful but you're not sure. In such cases, you might need to surf the net or look up a full-sized book to find out more.
As a quick reference guide, this pocket-sized guide is ideal, but don't expect any more of it than that. There are plenty of other CSS books, including some from the same publisher, that give much more extensive coverage. Those books can tell you a lot more but they won't fit in your pocket.