I used SWIG to generate the most of the Python bindings for me, it is a fantastic tool.
My code also has a lot of influence from chmdeco, by Pabs. He also has a very nice and complete CHM Specification on this web site.
GnoCHM was written using the excellent PyGTK libraries, by James Henstridge and others. Many of the questions I had about the Gnome and GTK bindings were already answered in the PyGTK FAQ. Most of the development documentation I needed to write a Gnome application was in the Gnome website.
And last, but not least, I would like to thank the people at #pygtk (irc.gnome.org), who were very helpful in answering questions and testing a few things for me.