The first thing you should do is to join the mailing list and attend a meeting!
We love presentations! Shoot an email over to the mailing list saying what you'd like to give a talk on and we'll help set everything up.
The website is now a wiki, so it is super-easy to add content. Just click on the "Edit" link down at the bottom of any page. This is an oddmuse wiki with a straightforward markup -- see the Text Formatting Rules page on the oddmuse site for details.
Here are a couple special pages:
If you need any oddmuse modules installed, just ask on the mailing list.