Plan your day around the Show's. They will typically put up their show schedule at the end of the month prior. So, the end of Feb, look up what the show schedule is for the day you're going.
I suggest seeing their three major ones:
One Ocean: the shamu show, featuring Killer Whales
Clyde and Seamore Take Pirate Island: Sealions, otters, and wlarus
Blue Horizions: the Dolphin show that also has some acrobats and birds.
There are a couple of other shows to consider:
Pets Ahoy: a show with cats and dogs; inside a small theater, be there EARLY (at least 30 mins) to get a seat.
Allure: Seaworld's Cirque de Soileil type show, no animals, just acrobats.
I would suggest planning on being at least 20-25 minutes early to each show, to guarantee a seat at the show.
It is possible to feed four different animals, all costing different prices and give you different interactions. But it's possible to feed Dolphins, Stingrays, Seals/Sealions, and Sharks. I highly reccommend the dolphin one if you want to actually get close to them. They don't come over if you don't have food. It is $7 per person to enter the feeding area and everyone going in gets food to feed the dolphins. Keep in mind, there are varying feed times throughout the day for dolphins, as there is a limited amount of food availiable. It's best advised to be there first thing in the morning, there is usually a feed right at the beginning of the day around 9:15-9:30. All the other places you can just by a tray of food for everyone to share. Stingrays are the only other animals you can actually "touch" as well as feed.
Happy Harbor, by Shamu Stadium would be a fun place for your kids to explore. It's geared towards kids your age. There is a Shamu Kids Coaster, a Carousel, and a few other rides.
Other Exhibits not to be missed:
Shark Encounter (walk through tunnel to see sharks underwater)
Dolphin Underwater Viewing
Wild Arctic (Beluga Whales, Walrus, Polar bears)-check the shamu show schedule, you don't want to be there when a shamu show lets out, it's where everyone from the show goes!
Penguin Encounter
Manta Underwater Viewing
Dolphin Nursery
Manatee Rescue
Hit up the exhibits between show times.
As for dining. There is one sit down restaurant, at the Shark Encounter, which you have to book ahead of time, and is a little pricey. Otherwise I'd suggest anything in the waterfront area of the park for lunch. Breakfast is pretty slim to nothing available so eat before you arrive.
There are also several different tours to take:
http://seaworldparks.com/en/seaworld-orlando/Attractions/Exclusive-Park-Experiences
Also, keep in mind that is the time of year they usually do Viva La Musica on the weekends. Meaning there will probably be more people there on the weekends that are of hispanic decent, and admission includes the concert for that day. Just something to keep in mind if you are or aren't interested in.
Hope that helps a little! Really, it's much more layed back there, and think of it more as a zoo/aquarium.
