You can find additional learning resources on the Autodesk website. See the following links:
MotionBuilder Learning Path: http:/area.autodesk.com/motionbuilderlearningpath
MotionBuilder Tutorials: http://www.autodesk.com/motionbuilder-tutorials
MotionBuilder User-to-User Discussion: http://area.autodesk.com/forum/autodesk-motionbuilder
Events and Seminars: http://www.autodesk.com/events