This was a surprise mini-vacation for my 4 year old son and 7 year old niece. I purchased my tickets on Ticketmaster ahead of time and I HIGHLY RECOMMEND that everyone do this. We arrive right at 9am when the aquarium was opening and there was already a line outside - I estimate 60-70 people. Luckily we didn't have to wait in line because we had pre-purchased our tickets. It wasn't very clear on where we needed to go, but we asked an employee and found that we could walk right into the "VIP entrance" and go to the Information desk for our entry bracelets.
Our trip was on 3/30, and I think this was the first Saturday of Spring Break, so I'm not sure if this is why there were so many people. The main part of the aquarium is set up like a "hub and spokes". There are rooms full of large tanks in each "spoke". In other areas of the aquarium there are shows (our passes did not include shows) and other special exhibits. My personal favorite was the beluga whales. They are sorta cute and I'd never seen a whale. There were 2 adults and 1 baby. Spectators are relatively far away from the whales so if you want pictures, be sure to have a camera with a good zoom (and no flash throughout the entire aquarium). In that same area is a large sea lion, but I think he is overshadowed by the whales; I caught a quick glimpse of him as I was leaving but could not stop to enjoy because of the crowds.
I think there is a cafe in the aquarium, but we did not eat there. There is also a hot dog card in a hallway that sells hot dogs, chips, brownies. Downstairs there is a vending area and lunch tables. We got hot dogs and ate down there.
We were probably at the aquarium for about 2-2.5 hours. When we left, the line to get in was probably 300+ people long. Again PLAN AHEAD!!