In addition to using Visual Source Safe for source control, you can also look into using CVS or Subversion. From what I hear, Subversion is easier to run on Windows & “better.” And both CVS & Subversion are supposedly easier to manage code, version, branch, merge, check out over the web, etc., etc.
FYI VSS is very very slow over a VPN. Very slow. You can’t imagine how slow.
I’ll try to post more later…we’re going to be looking into source control providers (including Subversion), so check back for a writeup on getting started with open source SCM.