Try the wxPython mailing list, which you can find on their site. And the best wxPython reference is the book (also available as an e-book) by Robin Dunn, who created wxPython. Seeing wxPython from his perspective is well worth the money. If I recall correctly he devoted an entire chapter to drawing with a canvas widget.
-Sandra -- http://mail.python.org/mailman/listinfo/python-list
