From the RR I've done so far with a group (all of one, so I'm no expert!) they recommend waiting on the cover so it doesn't get damaged while others are working on it. You might consider doing a spread or two inside your book so others can see your style, plus a sign in page where people sign their names and identify the pages they did. Course, this is your show Carolyn, so I'm willing to do whatever you set up! :-) This sounds like fun!
For those of you interested, get an old book and do your cover and your name page inside ...and then start "altering"...making it YOUR own.
If you send me your name, I'll start a list of those interested and after a couple of weeks or so, we can send the books on...how does this sound?