Some interesting read:
Compare TFS against others
If you want to select in between different source control tools, I did some search on the internet and found following articles with comparisons:
Happy reading.
Moving from SVN/GIT to Mercurial
Someone had problem with SVN and huge development teams. Read the story.
Mercurial branching
Talking about Mercurial, here is a guide on how to branch:
http://stevelosh.com/blog/2009/08/a-guide-to-branching-in-mercurial/
Source control statistics
People are using following systems:
CVS 12,6%
Git/GitHub 6,8%
IBM Rational ClearCase 2,8%
IBM Rational Team Concert 0,9%
IBM Rational Telelogic Synergy Suite 0,2%
Mercurial 3,0%
Microsoft Team Foundation Server 0,8%
Microsoft Visual SourceSafe 1,6%
Perforce 3,0%
Subversion 58,3%
None – I don’t use a source code management system 5,6%
Don’t know 1,4%
Other (specify) 2,9%
Source: Eclipse Community Survey 2010