I know I'm late to this thread, but there is actually a decent (if short) howto on python packaging for maemo in the last section of the tutorial on the pymaemo site. I used it as one of my main resources when I wrote Grumby last year (part of my motivation being in fact learning python + deb packaging).

The Grumby source tgz may also be useful as learning aid, since it's basically one python file with a lot of maemo/debian padding around. I remember looking at WordPy and other python packages for inspiration at the time.