page is a good place to start.
If you are trying to learn a version controlling system, let me tell you that CVS is not that popular as it used to be 10 years ago. I personally would not touch it. If you want a newer and more user friendly one try Subversion (svn), or better yet Git.
Subversion is a centralized VCS similar to CVS. But Git is a distributed VCS which does not need a centralized server to work. If you want to learn Subversion, the Subversion book
(free online) is a great place to start. If you are ready to go with Git (my personal favourite) then Git Docs
is a good place to start.
There are many VCS
s out there, if you want alternatives.