I believe you can buy bundled tickets for the aquarium, coke, and the Atlanta zoo. Check out the Zoo Atlanta or aquarium ticket page for more info. The Imagine It museum for kids is also fun and you can get really cheap tickets to see the Braves if you're interested. I am not a huge fan of the new coke attraction (it's kind of an expensive ad campaign- and I love Coke)- but kids would still like the tasting room. Stone mountain is another place to consider- pack a picnic and find a place on the lawn early (for free) to watch the laser show. The other attractions there are not free. If willing to drive a couple of hours south, Wild Animal Safari in Pine Mountain is great (rent the van!) and affordable. For kid friendly food: the Varsity (classic Atl), Mary Mac's Tea Room, and Marietta Diner. Have fun and welcome to Georgia!