You can actually book a room only reservation 500 days in advance. This must be done by telephone though. Package prices have, historically, be released mid-August. So, if you are looking for a 2011 vacation, check the Disney website mid-August, 2010.
If you were to book before the 2011 rates are out, your price will be adjusted to the 2011 rates as soon as they are published. So, there really is no advantage to booking early. Well, except that if you have your heart set on a certain resort, you will know you have that resort booked.
I would start posting questions on this site so that you can get an idea on where you want to stay, what attractions to see, where to eat, etc.. Keep in mind that there are a whole lot of different opinions out there.
I also highly recommend that you go to
www.allearsnet.com. They have an amazing site dedicated to Walt Disney World. You can find fact sheets on each Disney resort as well as pictures.
Allearsnet also has the menus for all of the Disney restaurants with prices. These menus will help you decide whether or not the dining plan would work for your group.
Go out and buy some really good guidebooks. My three favorites are the Passporter, The Unofficial Guide to Walt Disney World and Birnbaum's Official Guide to Walt Disney World.
The Passporter is fantastic for organizing your trip. There are lots of pockets, checklists, itineraries, etc.
The Unofficial Guide includes lots of details that some guides don't, like...height restrictions, best times to see an attraction, when to travel, etc. I do feel like the Unofficial Guide is a bit rough/harsh on Disney. But, I like it for the other information.
The Birnbaum's guidebook is a little bit sugar coated but it's a great companion book for the Unofficial Guide. They seem to balance one another out. Birnbaum's also has coupons in the back that can be used while at Disney.
I honestly don't know if I could wait until 2011 to go to WDW. We go each and every year (sometimes more than once a year) and I start planning our next year's vacation while we are still IN Walt Disney World. But, because we plan so far ahead, by the time the trip rolls around, we have everything done and planned and all we have to do is enjoy our time with Mickey and his gang.
Hope this information has been helpful.
Lisa