Hi Donald,
It all depends on what kinds of meals you and your kids like. There are many dining options throughout WDW, but most can be defined as either counter service or table service. The costs of a meal depends on many variables, but counter service meals can be about $11-$16 and a table service meal can be about $20-$45. This assumes you were to get an entree, beverage, and dessert. Kids meals for your 8 yr old can run about $5-7 for counter service and $7-11 for table service.
The dining plan give each guest one table service credit, one counter service credit, and one snack credit each night of their stay. You can use the credits in any order. The snack s can be a variety of things ranging from a juice box, to a fountain soda, to a candy apple, etc.
Decide whether your family would use the meals that are included. Maybe you don't like sitting down for a table service meal or maybe you like sit down meals exclusively. My family prefers to have appetizers instead of desserts and we don't often eat at counter service restaurants, so the basic plan doesn't make sense for us. There is also a deluxe plan that gives you 3 table service credits each day, but we find that to be too much for us currently. We're right in the middle of the two plans.
Last year we left with a few unused counter service credits and we still saved over 10%. If you can plan on eating a light breakfast using your snack credit, a quick counter service meal for lunch, and then a nice sit down dinner, you can save over 25%.
Review the
2008 Dining Plan Guide for more information