Version control is a critical tool for software development teams. Version control or revision control systems track changes to source code.
To learn about Git, the popular DVCS – start with this introduction to Git.
There is also a solid “Mercurial for Beginners” guide on StackOverflow that contains answers to most basic questions:http://stackoverflow.com/questions/1170338/mercurial-for-beginners-the-definitive-practical-guide. If you have helpful information to add, please do so there!
Of course, the Wikipedia article on DVCS may also be of use if you’re used to using (or have never used) a traditional version control system.