Whatever it is, it has to be very short and sweet. 9/10 people aren’t going to bother to plow through loads of stuff just to post a question. The more complex it gets the less good it will do b/c people will ignore it.
I gave my suggestion in the original thread about this.
The notion of a FAQ has been coming up from time to time for a long time. Its a good idea, but will probably serve more as something people can post links to. It won’t keep a lot of people from asking questions over and over again, but regulars can just post links rather than having to type the same stuff over and over.
A wiki-type site might work as something of a FAQ since a) entries are easily collaborative; b) there are lots of free or nearly free Wiki hosting services; c) its easy to post the URL’s to specific entries.