David, above all other advice I urge families to stay on Disney property. Disney has a three tier pricing for their resorts from value to moderate to deluxe as well as villa opportunities so basically all size families can find wonderful accommodations on almost any budget.
The benefits are immense but above all you will find that not having to rent a car is a huge benefit. You can take the Magical Express free service from the airports to your resort and return the same way at the end of your vacation. While you are there busses depart every 15-20 minutes from each resort to all parks and Downtown Disney. You arrive at Walt Disney World and can lock your keys in your safe for the duration of your visit!
Another big benefit is the extra magic hours for the parks. Almost daily one park will either open early or stay open late for
resort guests only. This is often the best time to see those popular attractions versus waiting in the long lines during the day.
Please review the resort benefits on the disney web site,
www.disneyworld.com. Check out each resort to see which best fits your interests and economics. There truly seems to be magic even through-out the Disney resorts!