Hi, Georgina!
If you will be staying in a Walt Disney World resort hotel, you can take advantage of one of many
Disney Dining Plans. We've found these to be a great way to pre-pay for our meals, cutting down on any surprise charges at the end of a great trip. Plus, we find that we get to order items that are a little pricier than we would have ordered otherwise, simply because we can do so at no additional cost!
Once you check into your resort, you'll be given a Key to the World account, which will include the total number of snack / meal entitlements your entire group may access throughout your stay. (Think of this as a pool of dining credits; on the traditional Dining Plan, this = 1 snack, 1 Quick Service and 1 Table Service meal per person per night of stay. A party of 6, staying 5 nights would have a total of 30 snacks, 30 QS and 30 TS meals in their "account.") All of these entitlements are valid until midnight on the night of checkout, so Guests may continue enjoying them even after they've checked out of their resort for one final day of fun. These plans also entitle each Guest to one resort-refillable mug, too!
If you are not staying in a WDW Resort hotel, and are a Florida resident, Disney Vacation Club Member or Annual Passholder, you may purchase a Tables in Wonderland Card, which offers cardholders a 20% discount on all food and beverages at "over 100 participating Theme Park and Resort restaurants (discount is valid for a party of up to 10 Guests including the member).
If none of the above applies to you, perhaps you should purchase Disney Gift Cards, which can be used throughout WDW for dining, shopping, etc. This will help you to set aside the amount you'd like to spend, without worrying about running up a credit card's balance.
Hope this helps, Georgina! Send more questions as you think of them!