I think the most important points one has to learn regarding source control systems are the following:
- the value of small, frequent check-ins/commits
- tagging, branching and merging
- rollbacks
- conflict resolution
- exclusive vs. non-exclusive checkout
- continuous integration
- Test-driven development & automated unit tests vis-a-vis source control systems
- forking
If you've got these major concepts covered, that's pretty much most of the things you'll ever need to know for source control :)
