I've been to Busch Gardens several times and it's a wonderful mixture of everything. You really need 2 days to see and do everything properly because it is a very big park. Lots of walking but virtually all flat ground.
If you have allocated one day, look on their website and pick a day with long hours so you can do as much as possible. Be there at opening time.
There is so much to see, but these things are NOT TO BE MISSED:
Rhino Rally safari ride: This is different to Animal Kingdom's safari. Do it first thing in the morning to avoid long lines. Also do it in the late afternoon if you have time. Each time you will see some animals better or they may be more active. Check what time the last safari of the day is, if you want to do it again.
Train ride around Serengeti Plains: This goes around the plains and around a lot of the park. You see lots of different animals on the plains. Stay on the train for the whole circuit and disembark at the station where you first boarded. It takes about 30 minutes to do the whole loop.
Sky Ride: These gondolas give a great view of the plains and some areas of the park. This could be skipped if you run out of time though.
Myombe Reserve: Wonderful walk-through area with gorillas and chimps that sometimes come right up to the glass walls. They have a new baby gorilla which may be on show when you go. Ask if the orangutans are on display yet (they were building them a new habitat). This area closes earlier than the rest of the park, so ask a staff member when they close so you don't miss it. Sometimes the primates are hiding, so try to walk through a couple of different times during the day to see them better.
Edge of Africa: Walking trail next to the Serengeti Plains. This trail has hippos (view them above and below water), meerkats, lions, giraffes, and lots of other animals.
Nairobi's Animal Nursery: Many animals indoors and outside in pens. Gorgeous tiny tamarins and marmoset monkeys. One pen even has armadillos and turtles together.
Curiousity Caverns: This is beside the nursery in Nairobi and has lots of nocturnal animals.
Tiger Island: You can see tigers and white tigers on an island surrounded by water.
Lory Landing: Wonderful walk-through aviary with various colourful birds. You can buy a cup of nectar to feed the lorikeets. They will all come and sit all over you!
Squirrel Monkeys: They are in a glass enclosure at the beginning of the line to Congo River Rapids. You can walk right up and watch them. You don't have to be in the line. They are absolutely adorable and easy to miss because I don't think they are shown on the park map.
Lemurs: They are in a big cage at the entrance to Stanley Falls Log Flume. Another one that is easy to miss.
The 2 best shows at Busch Gardens are:
KaTonga: Colourful African/animal-themed indoor stage show.
Wild Wings of Africa: Bird show.
The best, wildest rollercoasters are:
SheikRa
Montu
Kumba
Gwazi (wooden coaster with 2 different tracks to choose from)
Cheetah Chase: cute little family coaster that whips about all over the place.
The 3 water rides are a heap of fun:
Congo River Rapids (whitewater ride on round rafts like Disney's Kali River)
Stanley Falls Log Flume
Tanganyika Tidal Wave (big boat that makes a huge splash at the end)
Don't forget rain ponchos and sandals or water shoes if you want to stay dry! They have lockers at several locations.
You can check height restrictions for various rides on their website:
http://www.buschgardens.com/buschgardens/fla/default.aspx
Of course there are many other rides that are tamer than what I have listed above. They are just the best ones.
As far as restaurants, we just stick to quick counter-service places like these two (to save precious touring time):
Zagora Cafe: burgers, wraps, sandwiches etc
Crown Colony Cafe: pizza and sandwiches. This is in the same building as the Crown Colony Restaurant (which is a full-service restaurant), so make sure you go to the CAFE.
Their website has an interactive park map. You can also check daily park hours, show schedules, menus etc. I think the website even has a hippo-cam where you can watch them during park hours.
from Orlando to Busch Gardens during our Feb. trip. I believe the park will open at 9am the day we will be going.
and Kennedy Space Center on this trip. As much as it hurts, we will not be doing Disney. 
