I'm new to the Ext programming model and some of these things are pretty hard to figure out unless you know what's going on. Instead of going though the Kitchen Sink examples, which are good for understanding UI concepts but not the intricacies of templates, extensions, stores, etc., I've been pouring over the GeoCongress code. It's been a great help in learning about the whole process, but even then there are things that I don't quite get (will take some more poking around).
It would be great if someone could put up a tutorial walking through the GeoCongress example, pointing out the strategies that were used in various places. I think it would be a fantastic showcase allowing newbies like me to grok the underlying principles.