Hi, Maria!
I think you are referring to the
2013 Disney Quick-Service Dining Plan, which offers you so much more than snacks! (Of course...the snacks on this plan are fantastic, too; don't get me wrong. :-) )
I see that you are set to arrive on December 18th; that's good, because you can add Dining to your Walt Disney World Resort room or package up to three days prior to arrival. The 2013 rate for the Quick-Service Dining Plan is just under $41 per adult per night of stay and just under $12 per child (ages 3-9) per night of stay. If you plan on adding the Quick-Service Dining Plan to either a room-only stay or a room plus tickets, a Cast Member will be happy to convert your stay to a package which includes the Quick-Service Dining Plan at the rates quoted above. Call (407) WDW-DINE for assistance.
This particular plan entitles each adult and child on the plan (everyone who is on the reservation and is over the age of 2 must add the plan) to 2 Quick-Service Meals and 1 snack per night of stay as well as 1 Resort Refillable Mug (which may be refilled only at your Disney Resort hotel.) Quick-Service meals include one non-alcoholic beverage, one entree (and any sides which come with it) as well as a dessert. It's a great way to budget for your meals as well as enjoy some really fine food, too.
Our favorite Quick-Service locations include Be Our Guest Restaurant (Magic Kingdom-lunch only), Sunshine Seasons (Epcot) and Wolfgang Puck Express (Downtown Disney Marketplace); all of them have fantastic options which don't feel like Quick-Service at all. Yum!
Should you want tips on how to best spend your snack credits, send another question, Maria; we love to help!