Hi Jeff:
I have some documentation on my site you might find helpful:
http://rubick.com/openacs/
especially these articles:
A Quick Intro to OpenACS Templating - http://rubick.com/openacs/templating - describes how to use the OpenACS templating system.
Namespaces - http://rubick.com/openacs/namespaces - describes how to use Tcl namespaces.
Pascal's CVS article for OpenACS developers: http://rubick.com/openacs/contributing - note that I've asked Pascal for permission to put this up, but he hasn't responded either way. I will take it down if he asks me to do so. I've added some things to it as well.
Joel is in the process of improving our documentation (believe it or not, it used to be even less documented).
I also recommend that you document things as you learn about them. That's pretty much what I'm doing. That way, you pave the road for those that come along later. Using edit-this-page, it's easy to do.
You'll see my documents change a lot in the next few months. I'll be adding more to the document on the content repository, on adding workflow to a package, etc...
