Hi Brandy,
September is a good time to visit Walt Disney World if you are hoping to snag a special promotion involving the Disney Dining Plan. In the past few years, we have seen free dining offered more than once in September. I'll keep my fingers crossed that you will find a similar promotion in 2013.
I think your plan to book your rooms in advance is a good one, particularly if you have your heart set on a specific Disney resort or room category. Go ahead and book those rooms when the booking window opens. Then keep watching the
special offers page on www.disneyworld.com to see if new promotions covering your dates of travel are released. If you find one, call immediately to update your reservation to reflect the new offer. In the mean time, don't buy your theme park tickets separately because the special offers that include free dining typically require that you buy your theme park tickets as part of a vacation package.
If a special offer involving free dining does not become available for your dates of travel, you can still add it separately to your reservation for a fee. However, this cannot be done upon your arrival at Walt Disney World. You must do this at least 48 hours before your vacation begins.
Let us know if you have any additional questions, Brandy, as you plan your magical Walt Disney World vacation. We'd be happy to assist you.
Best wishes,
Jill