Advice for video or classes on channel setting

Best wishes for a happy 2004 to all. As a novice, I have learned a
lot from this forum and thank Hanuman and all of you for your
contributions. I hope to get a digital camera soon and have enjoyed
all the about camera’s and jewelry photography.

I’m in the planning stages of a project where I will be channel
setting square cut sapphires and onyx in a pendant. I have done
bezels, tube settings and fabricated pronged settings before. Does
anyone have a recommendation on a good video that demonstrates this
channel setting technique, or other suggestions about courses or
books that would be especially good for learning this technique?
The books I have do not seem to be very clear to me on how to
proceed. Is there any added difficulty in putting two different
stones side by side in a channel setting as long as they are the
same size?

Also, does anyone have a suggestion on where I could obtain small
(1/2 to 1 inch) dodecahedron crystals (12 sided). I understand this
is a natural occurring shape for several stones/elements such as
garnets, pyrite, diamonds and copper.

Thanks, Mary Collier Fisher, Walpole,Massachusetts