Your likely doing it right already. For the moment, there s an ample amount of blog posts from Django developers where they talk about doing Django development right and how they solved issues with testing some heavy-duty stuff, but not a single resource that covers it all, especially not with employing TDD exclusively.
If your into reading other people s source code, I think your on the best track of learning how experienced Python and Django developers do their magic, manage, test and redistribute their code.
I d suggest you make a commitment to hop over to GitHub, Bitbucket or Project Hosting on Google Code regularly and query for Django projects. It s great to get involved with something small that you can quickly sink your teeth into and really understand whats going on and maybe even go a step further and see how you can contribute.
Unfortunately, I m not aware of there being any Django project that s distributed with documentation on how development is being performed. It s not really the wild wild west: there s versioned documentation, wishlists, issue trackers, TODOs, branches and tags that show the development timelines, but not exactly something that covers the whole process from thought to a full, clean realization.
And too, unfortunately, most books deal with developing Django applications without a set development methodology. I think that s only fair, because people have their own way of doing things and tools that work best for them and a book like that would need to be at least 2000 pages long to cover all the variables..
I personally like to try doing something myself and then learn by example from other people by looking on what they ve done to address the same problem; I feel that gives me a full perspective with the rights, wrongs and whys of doing things. I recently decoupled an app from my project by using the contentypes
framework and I wasn t all too comfortable on how my tests turned out. I then looked at the tests from django-tagging by James Bennett and saw where my thinking went awry and it really helped me a lot.