cmd:cvs 

explanation 

The simpliest and clearest explanation might be that of using the sylpheed:

http://sylpheed.good-day.net/

help 
gnu cvs manual http://www.gnu.org/manual/cvs/html_node/cvs_toc.html
the HTML Cederqvist online http://www.cvshome.org/docs/manual/cvs.html
gnu cvs manual http://www.gnu.org/manual/cvs-1.9/cvs.html http://www.gnu.org/manual/cvs-1.9/html_chapter/cvs_toc.html

User manual 

The best is the one that comes with RH package, Version Management with CVS /usr/share/doc/cvs-1.11.1p1/cvs.ps

Finally realized that it *is* the 'gnu cvs manual'.

and the cvs info nodes.