I'm not surprised that you don't find anything. Very few projects are using it, and you can forget any idea of getting support on the internet. I'm searching for a way to get ATG, JBOSS, Eclipse working together so that I don't have to create & deploy an EAR every time a change a JSP!
ATG is the worst thing I've ever seen. Fortunately they have good salespeople. It's based on standards from 6 years ago and hasn't been updated much since then. Forget about all open source standards such as JSF/Tapestry/Struts, hibernate, spring, etc. and use only ATG proprietary frameworks (that suck mind you). For that you'll need an ATG consultant at 1500 euros/day, who will of course fly in from out of town and therefore not be very productive.
ATG should die. I don't want the agony of working on another ATG project. I will resign if my company accepts another ATG project!
I have been using ATG for the past 4 years and it has it's good and it has it's bad. Class and properties reloading requires restarting the appserver instance (yuck!). I am currently evaluating running it on JBoss. We currently run on IBM Websphere and it's a memory hog, disk space hog, and has quirks when it comes to getting it running with ATG. I think JBoss will work out well with ATG. As for whether to use it or not, depends on the use. We use if for our public site and it's overkill. But we also use it for our password protected, customized on a user basis, extranet site and it works well for that purpose.
ATG documentation on the web is non-existant, their support site is extremely hard to use, but they do answer their tech calls on the first try. Phone support has been pretty good to me, but once again, their online support site really needs alot of work.
We're running ATG 7.2 on JBoss in production and have it running in Eclipse. What are you looking for help with?