Hi, Melanie! If you know which parks you are going to be in on which days, plan your meals based on that schedule. If you'd rather not plan in advance, maybe you could reserve some meals at resort hotels, so you can leave the park you're in for a nice meal, then head back to the park.
If you want to work out a schedule based on where you'll be, start with the calendars. You can find what you'll need with regard to extra magic hours, parade schedules, and fireworks information at
Disney World Parks Hours. Once you figure out where you'll be when, you can start filling in your dining reservations. You can most of them by visiting
Disney World Dining Reservations.
Dining reservations open up 180 days in advance, so as soon as you know where you want to eat, you want to make the reservations. The character dining experiences tend to be very popular, and they can fill up. There are other very popular meals, such as 'Ohana at the Polynesian resort and Le Cellier in EPCOT's World Showcase, which you'll want to book as early as you can.
I hope this helps with your planning!