Well, first thing you want to do is reply to this (http://community.livejournal.com/damned/271407.html) post with the introduction post.

After that, you'll see posts being made like "F1-F10 Hallway", "F11-F20 Hallway", etc. You can just pick one of those at random (since Jaenelle doesn't have an assigned room yet), and start posting from there.