What are the must see places in and around SF?
Golden Gate Bridge.
Ride the street cars (the only 'moving' national monument in the United States).
North Beach for some interesting restaurants.
ChinaTown - not just 'main street' where all the tourists go, though. When you are in the heart of Chinatown, go at least one block off the beaten path and you will see a Chinatown where there are little souveniers, but a lot of the Chinese culture.
And without a doubt, Alcatraz is fascinating, but get your tickets early, way early. If you are looking at visiting in the summer during tourist season, you may want to get your tickets at least a month in advance.
The Wharf - mostly shops these days, but there is a place where you can see the seals hanging out on rafts. You can get within 20 feet of them. You can also get fairly close to some ships that have been permanently docked and there is a submarine tour (for a price).
It is important to know where you are going - you do NOT want to end up in the area called the Tenderloins.
Make sure you get a manicure while your there! There's a shop on every corner and the price is right. San Fran is one of the best places for good food. Enjoy! Also, if you go in August, be sure to bring a coat. If not, you can always pick a pretty nice one up in a thrift store for 5 bucks. (Great thrift shopping, lots of hard back books read 1 time for a couple of bucks). Enjoy!! It's one of my favorite cities.