Confirm you have been granted access to the site. To request access, submit your PMI profile information at the bottom of the Beta users page. When access is granted, you will be notified.
Login to http://agile.community.pmi.org/ using your PMI profile username/password.
Get comfortable with the layout and click path by flipping through the instructions here: http://agile.community.pmi.org/Pages/shareddocuments.aspx?Filter=Documents%2FSharePoint%20Tutorials
Post something of value/interest as follows
1. Make your profile publically viewable by clicking "make my profile visible" on this page: http://agile.community.pmi.org/Pages/members.aspx
2. Pages from wiki can be copied here: http://agile.community.pmi.org/Pages/CreateWiki.aspx (Note the wiki pages in SharePoint are flat, and can not link to each other
3. Flat files can be posted here: http://agile.community.pmi.org/Pages/shareddocuments.aspx
4. Upcoming Events should be posted as announcements here: http://agile.community.pmi.org/Pages/AddAnnouncement.aspx (note: the calendar feature currently does not work)
5. Create a threaded discussion related to PMI Agile
Be sure to create an announcement highlighting your post, by clicking here:
1. In the BODY field, be sure to include a link to the posted item
2. In the EXPIRATION DATE field, put 12/31/2009

The website has two kinds of admins: Sys Admin (PMI) vs. Site Admin (Council)
Right now, can't delete/modify the 7 default folders in Shared Documents . Will come soon.
Right now, can't redesign the home page. PMI investigating new color schemes.
Yes, they can help you import threaded discussions. A request has been submitted to import our Yahoo discussions.
Right now, only webinars can go into Calendar. In the future, you can add custom events.
Blogs are created by IT. They need 2 days lead time. Blogs are assigned to Users or Groups
Have asked PMI for list of estimated target dates for IT upgrades

How to Post to the official SharePoint site