Best thing to do in San Francisco is to get around. See the Golden Gate Bridge, SF MOMA, Fisherman's Wharf, Palace of Fine Arts, and a whole lot of other places. Since California is a fusion of cultures, restaurants with specialties from all over the world can be visited in San Francisco.
Quick Tips:
Don't forget to bring a light jacket or sweater when you go around San Francisco. The wind can be chilly, especially during the late afternoons.
Restaurants require a 15% gratuity for service rendered.
Best Way To Get Around:
Renting a car is the best way to go around since public transportation can take a very long time when you want to go to a certain destination. The BART and Caltrain routes are easily accessible on major thoroughfares. Trolley shuttles can get you to most tourist destinations at a minimal fee.