AMK wrote this very interesting article, discussing the architecture that he and the MEMS Exchange team used to implement a complex web based application.
I'm particularly interested in looking at Quixote and ZODB.
Now I re-read the article, though, Grouch looks worth a look, too. unittest less so, since PyUnit made it into the Python standard library.
Untitled Document used to be one of the funniest sites in the 'net.
But then the updates became intermittent, then stopped altogether. Shame.