Topic from last year by a github employee:
http://www.chiefdelphi.com/forums/sh...ghlight=github
Page for requesting an educational organization account:
https://github.com/edu
The FIRST Octocat

:
http://octodex.github.com/FIRSTocat/
EDIT: I should clarify, I believe when I signed up they asked me how many private repos I would like for the group (I asked for a few and was given as many as I requested). Public ones are unlimited, though.