Programming in Scheme
This page lists resources for learning to program in Scheme. It should be particularly useful for the GNU Generation project, but it's also intended to be of general usefulness.
GNU Robots is a simple game which you play by writing instructions for a robot in lisp. When you launch the game, the robot follows your instructions. You can't control the robot after the game is launched, so the "playing" part of the game is writing the instructions.