Clint --
I've just made my first steps with pre3d out of this demo:
http://www.html5canvastutorials.com/labs/html5-canvas-pre3d-rotating-cube/
I do have a few years coding javascript and it took me about 3-4 hours
to get something really basic.
One thing that I found was that there is some 3d math and concepts
that you may need to understand how these 3d libraries work.
Hope that helps.
Ignacio