Ok first there are many source control products other than the two you have mentioned but I would get used to SVN first.
TFS is expensive and tied into the Microsoft stack.
I'd start with reading this:
http://svnbook.red-bean.com/
Specifically the chapter on fundamental concepts
Yes this book is tied in to svn but it covers the basics too.
When you have read that download TortoiseSVN. This is an svn client that hooks into your windows shell. Only when you are comfortable with using this would I then move on to an integrated svn client. (I actually don't use one) AknhSVN is free.
