Esinem’s Shibari Classes: Esinem has probably got the best free safety course I’ve run across so far. I got hold of it by buying his “Tying People, Not Parcel’s” DVD, however the same information is also in a free online tutorial. All it requires is creating an account and enrolling in the course. Of particular interest to me was the in-depth section on nerves and nerve damage, and tying a safety line to prevent mishaps.
IPCookieMonster’s video on anatomy for rope bondage; this thing is very cool, highly recommended.