To get started, here's what we need to do:
1. Find a venue. Definitely the hardest part of the process. Venue donations are ideal!
2. Pick a date. Once you've got a place picked out, figure out when you want your event to happen. We've tended to try to hold Barcamps simultaneous with other events to mix up the attendee pool -- since you'll draw from both local and out-of-towners. What's most important is that it's convenient for you and works for your community.
3. Communicate. Blog, Email, IRC, wiki and document everything! Seriously, the more transparent and communicative you are about your Barcamp, the more successful you'll be.
4. Say what you need. Participants can be helpful and giving -- but if they don't KNOW that you need a few extra dollars to cover catering lunch/breakfast, t-shirts, whatever, then they can't step up to the plate and help. Remember: everyone participates. So, give everyone the information they need to be able to participate!