I would also like to see a short section (perhaps in the form of a FAQ) that could be linked whenever someone asks for Python help on python-dev/python-ideas, or proposes an idea on python-dev, or "misuses" the lists in a similar fashion.
These could then be linked with a short message such as "Python-dev is about the development of CPython, not for general Python help. See devguide/communication.html#faq-asking-for-general-python-help".
As for the "Quick Start" I'm not exactly sure what you want to put in it, but I'm not sure whether it should be added alongside the main quick start and if it should be called a quick start (I don't think people ask themselves "I want to communicate, where do I start?").
I think expanding /devguide/communication.html (and/or devguide/help.html), adding a list of guidelines at the top and description/faqs of the MLs should be enough.  A link in the main page (perhaps even in the "coding" quick start) could also be added.