Materials
From NVCWiki
CNVC's store: http://cnvc.org/matls.htm
Free written materials from CNVC (this page has chapter one of the Nonviolent Communication book, and in the right column are links to many other materials): http://cnvc.org/bookchap.htm
Puddle Dancer Press (publishes many NVC materials): http://nonviolentcommunication.com/
NVC Dance Floors offer a way to dance your way to learning NVC.
The Learner centered differentiation exercises are designed to help participants discover the core principles of NVC for themselves.