Hi Megan!
A 7 day trip allows you 2 full day visits to the Magic Kingdom and to your second favorite theme park, 1 full day visit to the other two and 1 day to rest and enjoy your resort.
If budget allows, staying at a Deluxe Resort allows you to be closer to 1 or 2 theme parks or to Downtown Disney - a convenient benefit that allows more time to sleep and to be at the parks.
Using taxis or your own car (or a rented car) will also allow you a shorter commute between any resort and theme parks.
Time is precious during any vacation.
Disney offers
attractions, special events and restaurants for any taste and budget. I suggest spending some time getting familiar with these and trying to determine which your family will enjoy the most.
Also, you can get to view the menu of each restaurant - most of which includes prices.
As one of my personal favorites, May is a great time of the year to visit Disney and enjoy special events like
Star Wars Weekends and
Epcot International Flower and Garden Festival. Both events only require regular park admission.
To schedule daily activities you can use
Walt Disney World Calendar, where you can see park hours and events times.
As you get familiar with the different activities feel free to visit and ask any other question about your vacation.
Hope to hear again from you.
Miguel