Parking is right at the pier. I think it's $11 for every 24-hour period, but DO call your cruise line and double check that figure. If you would arrive a day early, several hotels have a Park and Sail package in which they keep your car and shuttle you to and from the ship. We will use the Sheraton. Hope this helps, and happy sailing!
I believe Judy is talking about the Port of Los Angeles in San Pedro. For Long Beach, the Port of Long Beach is real close to the city and there are several hotels offering park and sail type packages. We stayed at the Courtyard by Marriott downtown and they have a package that gives you a ride TO the port. You'd be on your own getting back, but the taxi charge is around $6 per carload. I understand that the Coast hotel has a package but don't know if it includes round-trip transportation. There is a multi-level parking structure, but I saw a lot of cars parked out in the elements. Can't answer your question about security, it looked like anyone could drive in to the parking area. This is right next to the Queen Mary. To get the real info on parking rates, call the Queen Mary desk, since people who stay there with their cars have no choice but to pay the port parking fees.
Actually, there's two parking places at the pier. The first one's for the Queen Mary, and for the ferry to Catalina Island. The multi-story one is for the cruises. It's secured, safe and it's $10 per every 24 hr. period. We were on a 4 night cruise, and paid $40 on our way out. It's really an easy access to the ship.