I also like philosophy, physics, astronomy, good literature and Mudkips. I've had some recognition in the fields of math and mathematical linguistics, but I very much wish to achieve more. I also like staring at Bammes' work blankly.
So... I hope we lead many ferocious discussions here.
Here's a guide that I previously wrote in another thread to help get you started on Planet Tolkien.
There are different types of forum for different subjects. The one you posted on is for greeting newcomers, as you found out, but there are also ones for discussing the books/movies, the website in general, polls, Tolkien-related trivia, games, posting your own stories and poems, and many other things that I can't think of at the moment. You can even create your own character and journey through Middle-Earth with other members in a Role-Playing Game (RPG). Drop in at the Khazad-Dumish Inn, or go on a more dangerous adventure in A Dark Threat from the North or Eruheran's Quest, the three active RPGs at the moment.
Editing your account: You can change different features of your PT account through 'My Account' (top left on menu bar). You can upload an avatar (picture when you post, must be 70 by 70 pixels and must be in .gif format), change your personal info, post Journal entries, view updates on PT, and send Private Messages (PMs) to other members if you want to alert them about something. However, it does cost mithril (20 pieces of which you get when you login each day). It depends where this member lives in PT (I, for example, live in Osgiliath, and you in Lothlorien, so it'll cost something along the lines of 5 pieces to send). It costs 400 mithril to change your location.
Under some members' avatars you may see a little black box with 'Council Member' written on it in white letters. They are a part of the Council for being old and distinguished PT members (hope I didn't just offend anyone - hee hee) and have administrative powers, meaning they can edit other people's posts if they go against website rules (we are a Family Friendly website, so no swearing or profanity please).
And most of all, enjoy PT!
And don't vanish like all the recent new people have.
But it'll pick up again when the Hobbit films hit the screens!