1. cvs tag
2. modify some code and build the release.
3. make patch (I use tortoriseCVS)
When you want to apply the patches, first make sure you can the patch is for what 'tag' version. after that
1. cvs co -r "tag" "module name"
2. go to the directory you just check out the source code.
3. patch -p0 < "your patch file"