This looks good from an overall why you should learn it point of view and also to help you with the lingo that you should know:

http://betterexplained.com/articles/a-visual-guide-to-versio...

For IT people you should have your /etc/* files under revision control to track any changes and easily roll back changes that break your system. I actually think there are some tools that are specifically for this purpose and not the general purpose SVN/git/hg variety but I cannot think of them off the top of my head.