DNNCreative doesn't focus on module development simply because most DotNetNuke users are not developers. I would seriously recommend that they NOT deal with source code versions of anything. There are occasional exceptions, but they really are minor. Developers won't have trouble.
For developers, there are great resources such as Michael Washington's adefwebserver.com site and
Mitchel Sellers book on DotNetNuke module development.
We do have one tutorial that might be of interest to budding developers/modifiers:
How to improve a DotNetNuke module (The Blog module)