Hello, Rebecca,
Guests can begin making reservations on August 14, 2012, at 7 am. If you happen to be a Tables in Wonderland member, an Annual Passholder, or a DVC member, you can begin making reservations on August 10, 2012, by calling 407-WDW-FEST. You can read more about making reservations
here.
When the date draws closer, I'd encourage you to call the above phone number to confirm the times/dates for bookings just to be safe. You may also want to visit the
Disney Parks Blog, the Epcot International Food & Wine Festival on Facebook, and www.disneyfoodblog.com regularly since they will likely be sharing information, too.
Happy dining!