Know someone who could use a clear, hands-on introduction to GitHub? @nettuts has them covered.

img http://img.skitch.com/20100118-mbutj6e8irbau8ms7uach741i1.png http://net.tutsplus.com/videos/screencasts/terminal-git-and-github-for-the-rest-of-us-screencast

Their Terminal, Git, and GitHub for the Rest of U (which compliments their excellent Getting the Hang of GitHub tutorial) is a great introduction to Git and GitHub.