Anton Setzer offers good course documents on interactive theorem proving with Agda:
http://www.cs.swan.ac.uk/~csetzer/lectures/intertheo/
The Agda CVS repository can be browsed at http://cvs.coverproject.org/marcin/cgi/viewcvs/Agda
Some CVS snapshots of Agda are available from
http://www.coverproject.org/Agda/