Try Git
Today we're launching a unique and easy way, in the format of a Code School interactive course, for new Git and GitHub users to try both the tool and the service without a single bit of software installation.
If you know of a developer, designer, or other knowledge worker that would benefit from using Git but that hasn't made the leap just yet, send them over to try.github.com when they have a spare 15 minutes.
Made from 100% real Git and GitHub
This site even interacts with GitHub via OAuth and will push your resultant tutorial repository to your GitHub account as a repo named try_git.
Pairs with Intro-to-Git Videos
If you are interested in a matched set of introductory Git videos, check out the video page of the Git SCM site too.