By Karl Fogel <kfogel@red-bean.com>
This book was published some time ago, and does a very good job of explaining how to use CVS. The interesting fact is that most of the book is Open Source, and freely available at the above url. "Chapters 1, 3, 5, and 7 deal with the challenges and philosophical issues inherent in running an Open Source project using CVS", and are only available in the deadtree version of the book.
Apparently a new edition has been published, and the new PDFs will be uploaded soon.
see also Software Engineering Resources, CVS