This book is a practical guide to CVS which addresses both users and administrators. It is composed of an introduction, a user guide, an administrator guide and a reference section. The introduction is the section I liked the least; in my opinion there is too wide a gap between the general description of what version control is and the subsequent quick tour of the features of CVS. Maybe a few pages could have been devoted to a description of the common tasks of version control management. These topics are indeed covered in the subsequent sections.
The user guide and the administrator guide are both fairly complete and combine a description of the functions available with advice on how to make the most of them. The reference section not only covers command syntax but also the file formats and environment variables. I did not have the opportunity to verify it thoroughly, but it seems to be accurate.
The author appears to know her topic very well and manages to present it clearly, even though I found her style a little awkward here and there and many concepts are repeated almost verbatim in different places. However these defects do not detract from the overall quality of this book.
It should be noted that this book only covers the use of command line CVS on Unix/Linux systems; graphical front-ends and solutions for other platforms are briefly covered in an appendix. Nonetheless I am convinced that "Essential CVS" is useful even to those that work on different systems.
Lastly, it may be just a matter of taste, but I find the 300 page format very convenient: I do most of my technical reading while travelling on public transport and I appreciate books that I can carry with me without breaking my back in the process.
This is a book that delivers what it promises to its target audience. If you are a CVS user chances are you will never need another book; if you are an administrator it will still cover most of your needs.