well welcome to the verse - proffers free shiny stuff :o)
definately check out the comics and the visual companion if you want more firefly. the comics fill in the gap between the cancellation of the series and the movies and the River Tam sessions (5 of them - search google) fill in some more on River's time in the Academy. there is also the movie novelisation and another book called "Finding Serenity" - it's a book of essays on the series - very worthwhile.
also on the web you can find a script for "Dead or Alive" which was possibably going to be the next Firefly episode before the show got axed - not 100% certain of it's autenticity but is a damn good read nevertheless.

Goody! Another link in the chain to relighting Firefly. Go you! Not that you arn't special in your own way. Just every person who becomes a Browncoat means we are a little closer to getting our 'verse back. We have done the impossible and that makes us mighty!

welcome, we are glad you've joined up...
soooo
have you read the comics?
Have you watched the Tam Session videos?
Have read the Visual Companion (Joss' shooting script for Serentiy includes a lot of goodies)...
and don't worry, there will be a sequel,
it probably won't get green lit until next year, but this 'verse is NOT going away!

Oh Bravo, you deserve a caldicot award. Yeah, I'm full of it and I know. Oh well