Chula Vista is a ways south of anything worthwhile, but you can probably save some money on hotels by staying down there. Depending on what time you get going in the morning you'll hit some traffic heading north towards downtown. Balboa Park is just off downtown. It's not that far, though, so you'll probably be OK.

You might want to check out the Marriott on Coronado. They are just wrapping up a renovation and may have a good deal. Anything near the airport is going to be a lot more centrally located than Chula Vista. Coronado may look out of the way, but you'll be going against traffic morning and evening.

Be sure to check out the Maritime Museum on Harbor Drive, also the Midway aircraft carrier museum.

The Fish Market Restaurant on Harbor Drive is great for fresh fish at a reasonable price.

Little Italy (India Street) has some great sausage sandwiches (Pete's - closed on Sunday) and gelato (ice cream) at Cafe Italia.

Roberto's is a fast food local chain. It's probably OK.

Cabrillo Monument, the Lighthouse and the nearby tide pools are great.

Depending on how old the kids are there is also Legoland, and Sea World.