Getting here should be easy for you as well as getting around. There are several airports that serve most of the world. This site pretty much breaks it all down with fabulous links: http://www.sfgate.com/travel/resources/airports/
SFO or San Francisco International: is THE place to fly in/out of for international flights and for easy BART and CalTrain access. This is the airport we use most often. Jet Blue, Virgin America and Southwest fly out of here and of course all the other domestic and international carriers.
OAK or Oakland International: is in the East Bay. Cheap flights in/out of OAK and it's BART accessible. If you are staying in the East Bay, Berkeley and points east beyond, this is your airport.
SJC or San Jose International: is in the south bay is an alternative if you are visiting HMB or Silicon Valley or Santa Cruz. Cheap southwest flights but no access to BART and it's pretty darn far (an hour at least) from downtown SFO.
Rent a car? Well, eh. If you aren't acclimated to big city driving you are going to be really annoyed driving here. If you are staying in SF (downtown) then you are CRAZY to rent a car. You don't need a car unless you are headed out of town (like going to Marin, wine country, HMB and points south). You can get to Oakland and Berkeley very easily by BART. Parking on SF streets can be tricky and spots in some neighborhoods are nonexistent. Hotels have garages but plan on spending up to $30 a day other garages can charge per 15 minutes. Taxis make getting around the city easy and there's the more affordable MUNI system as well.
