Greenfoot

 Greenfoot site

http://www.greenfoot.org

The Joy of Code

http://www.youtube.com/user/18km?ob=5#g/u

Introduction to Greenfoot

https://www.youtube.com/watch?v=NcGe141R2yA

Tutorial

http://www.greenfoot.org/doc/tut-1

Greenfoot collections

http://www.greenfoot.org/collections

Greenfoot scenarios

http://www.greenfoot.org/scenarios