Tutorial on how to use GIT for Version control with the Source SDK
Introductory tutorial on how to use Tortoise SVN for versioning files.
A tutorial covering the basic usage of mercurial for version control.
Concise Tutorial covering the basics of using GIT in a windows environment with a GUI.
Detailed Tutorial covering how to use Perforce to control your Source Code and Assets.
Illustrated Tutorial on how to use GIT through msysgit on windows.
An old but indepth tutorial on using P4V.
An online book that goes in deep with mercurial for source control.
Older tutorial on how to get up and running with Subversion through tortoiseSVN.