The biggest difference is regional: Hedgewitchery is old European and Shamanism is more ‘New World’ or common to the Americas especially among the Native American.
they different in some ways while the same in so I’m not sure. I hope I helpeds just a little.
here a few website maybe this will help http://en.wikipedia.org/wiki/Contemporary_witchcraft
becoming a shaman takes a life time.
the other sounds like tv.