CVS Pocket Reference by Gregor N. Purdy, published by O'Reilly, August 2000. ISBN: 0-596-00003-0. URL: http://www.oreilly.com/catalog/cvspr/. Provides concise information on installing and using CVS. It details the administration files used by CVS and explains CVS commands and options. It includes pointers to Perl modules, clients and web interfaces that can be used with CVS.
Open Source Development with CVS by Karl Franz Fogel, published by Coriolis Inc., November 1999. ISBN: 1-57610-490-7. URL: http://cvsbook.red-bean.com/. Contains detailed instructions on using and administering CVS for local and remote users along with insights into open-source development practices and philosophies. A nice feature is a chapter of CVS hints for troubleshooting that includes actual situations encountered by the author. Most of this book is released under the GPL and available on the publisher's web site.