TortoiseSVN is a really easy Revision control/version control/source control software for Windows.
Since it's not an integration for a specific IDE or interface you can use it with whatever development tools you like.
TortoiseSVN is free to use. You don't need to get a loan or pay a full years salary to use it.  I have been using this software for about 2 years and it has saved my but numourous time.  I just role back revisions when my release doesn't go right.  It also has a excellent difference viewer so that i can figure out what went wrong with my recent changes.  Whether its a simple html website or a full blow development project this stuff is a must.

Check it out here for windows: 

If your not a windows user or wish to run a server version go here to learn more:

For a less intense versiioning system check out file hamster.  Not quite as powerful but a little easier to use for someone who is as tech savy.