Did you know if you go to the Baltimore Aquarium on a Friday after 5pm it is half priced? I really enjoyed my trip here. It was really nice and there were plenty of things to look at. There were dolphins, sharks and all kinds of jelly fish. My personal favorite area was with the dolphins.
Afterwards the baltimore harbor area is just bustling with things to do. There are lots of places to grab a bite to eat and there are some stores if you are into shopping as well.
Parking is hard to find and on the pricey side. Try getting parking online for a better deal.