CVS help

Can anyone recommend to me a website or the best book to read about learning how to use CVS?? Ive applied some of the customizations found in the gallery forums to the gallery on my website, however when upgrading to newer versions, these changes are always lost and need to be put back in by hand. I know the way to get around it is with the CVS branching feature, however after spending a few hours looking at the official CVS site and documentation, I am still bewildered how to implent or even create the branch. (I know it cant be that hard :cry: ) Im using the cygwin cvs to modify or download the new sources from sourceforge.

Any input by any knowledgeable person would be appreciated. :o