I have been working on a project with a similar goal.
I accumulated a big list of links to documentation, tutorials, best
practices and miscellaneous notes, and put them in a virtual mixing
bowl, shook well, and built an application called "Google Apps for
Dummies".
Check it out: go to
gae4dummies.appspot.com and look in at the "Link
City" page, especially the "Good Ideas" and "Good Code" tabs.
There's a lot more material yet to go onto the site, and I have been
pondering whether or not to post material in a wiki format - but I
don't know how easy it will be to "moderate" the site, and keep it
both organized and 'relevant', to use a favorite Google term. What do
you think? Would anyone volunteer to help maintain such a wiki or
similar repository of useful stuff?