San Fran is a remarkable area. It's hardly the cliche' you would expect. Nice people, fun venues, and pretty decent weather for the most part. Beautiful women are there too.
Coit Tower is a neat sight seeing ordeal, coupled with a stroll down Lombard Street to the Embarcadero (to the Fisherman's Wharf) and a tour out to Alcatraz would make a day out of one sight seeing tour.
Then you'll need to do the Golden Gate. The city is rich in history; I hear they got a good baseball team, too.
Farewell brother, I hope the West Coast blesses you.
Totally agree with Johnny - also Alcatraz is an impressive tour. Golden Gate park is a great time. Chinatown is an experience - like no other Chinatown I have ever been to in any other city.
Restaurants are amazing. Traffic sucks. Good public transportation.
Don't give one damn cent to any homeless people there. If you do, you will be bombarded from every direction. The are like pigeons on some bread crumbs and they can be very abrasive about it too. I am all for giving some spare change to people down on their luck, but the only place I don't do it is in San Francisco.
Also, don't call it "San Fran" or "Frisco". They hate that for some reason. Never figured it out, but they will get up in your ***t if you do!
Fun fact: More alcohol is consumed in San Francisco per capita than anywhere in the US. And, trust me, its true. They know how to party there!
There are some great areas outside the city. You can over to the East Bay and there are some gorgeous suburbs, but you are still close enough to take public transportation (BART) in to the city. Walnut Creek is great. San Ramon and Benicia have some nice areas too.
Sorry for the long post. To sum it up: Don't give to the homeless, don't call it "Frisco", and be prepared to drink.
I'm out!