Last Summer I conducted a training course on Ajax Web Development. I was basically a substitute teacher. The presenter couldn't make it, so I filled in and presented their material. I created this as an addendedum to the course because if you're doing any kind of serious JavaScript development, using the FireBug debugger is essential. It's probably a little dated now, since I think it was from 2 versions ago, but should still be helpful.
HTH,
JOhn