When I'm not gardening, I work in the Department of Horticulture at Cornell University. One of our professors, Ken Mudge, teaches an online grafting course that's also very hands-on. He sends plant material (hibiscus) and supplies that you actually use for the 'lab' part of the course. He also teaches the principles so that you can apply what you learn to other species and situations.
The picture is an 'arborisculpture' made by one of Dr. Mudge's students.
If you want more information on the course, please see our website at: http://www.hort.cornell.edu/grafting/
