I'd agree with you that DVD Architect (and, by extension, Architech Studio) is not the most intuitive product, though it is pretty powerful.
Vegas Help is actually some of the best help I've ever seen supplied with a product - but it's perhaps better for detail than for "how to".
I presume you've looked at the interactive tutorials (under "help" in the menu).
Another good source of instruction are the Manuals - downloadable from www.sonycreativemedia.com
I've not looked at it but www.vasst.com create some very good instructional video DVDs and they have one for DVD Architect.
Failing that, if you really cannot get on with DVDA, I'd urge you not to give up on Sony Vegas itself, but to look at using a different DVD authoring package. That way you won't waste what you've already learned about editing in Vegas.
As I use DVDA I'm not really in a position to recommend alternatives, but I'm sure others on the forum will.