If you’re jointly writing code with others, use Mercurial or Git. (Not SVN. Linus explains, but the quick version is: you can’t commit offline.)
Sites like bitbucket, github and Google Code let you maintain your code online with others editing it.
My preference is for Mercurial via TortoiseHg, which integrates well with Windows Explorer. (I use the command prompt, but people I collaborate with prefer this.)
Here’s a 2-minute video explaining how to install TortoiseHg and commit your code onto bitbucket.
What a perfect time; Couldn’t have been timed it better (for me). I am about to start my own company in Chennai & all these open source tools will be of immense help. Thank you Anand.