Sorry about the delay in returning to this thread. I was talking to the web design person last week as the answers came in and wanted to wait until I'd heard from him. Then I forgot to return to it.
The AHDS primers have all been very good, though I believe not all are completely up-to-date. If you are new and don't know about these (and if you are not new and don't know about them, it is worth repeating the address Robert Haug gave us http://www.ahds.ac.uk/creating/guides/index.htm.
The project management is also huge. Humanities computing projects are almost invariably underfunded and especially understaffed, meaning that a person with a PhD in some arcane medieval speciality also has to become a specialist in the arcana of markup languages in order to bring their work to market. It was partially to improve that process that we decided to set this up: hopefully we can improve efficiency by pooling the "secondary" knowledge we have acquired in the course of our projects.
What I was asking our web designer about was including a wiki-style encyclopedia in the site. I believe we are going to be able to do it. For those of you who don't know what this is: http://www.wikipedia.org/ This is an encyclopedia that is built and edited by the community of users. I'm not up 100% on the organisational details of the link I've just given you, but in essence, a member of a community writes an entry, and this is improved on and/or edited by other members of the community as they are able to do so.
There is some danger of vandalism, of course, though this appears to be a minor problem (and would be especially in a small group like this), but it is a particularly good way of building up a knowledge based aimed at a specific community. It is less good at progressive knowledge (i.e. a series of lessons), but is very handy otherwise.
A second thing we have been tossing around for a while involves developing guides to best practice. A very good one for medieval Norse is http://helmer.aksis.uib.no/menota/guidelines/contents/contents_1-1.html.
If particular sub-communities were interested in developing these, we would publish them as a subsidia series. Cheers. -dan