I've been wanting to do something like this for a while, but now I have an excuse! A friend of mine from Leicester is visiting the Bay Area for the first time with her husband, and they're trying to plan their week. So here are my suggestions, starting with San Francisco itself...
San Francisco Itself
First of all, the basics. San Francisco is great for walking, and the public transportation is unusually good for the Bay Area. You can figure out how to get around using www.Transitinfo.org.
Go to the Ferry Building on a Tuesday, Thursday, or Saturday, when there's a farmer's market on. The bad news: everything costs more than it should. The good news: it's all really, really good and the market is a lot of fun, especially on a Saturday. My favorite store is the Stone House olive oil stand; Recchiuti Confections is also excellent. For lunch, I like the bento boxes at the strangely named DELICA-rf1 and the sandwiches and homemade potato chips at LuLu Petite. Stop by the Ferry Building store for information on whalewatching tours, trips to Alcatraz, and ferry schedules.
Sightseeing in SF: You might consider doing a walking tour of some of these areas, on your own or with a group. The San Francisco Public Library offers tours.
You can easily wander on foot around North Beach and Chinatown; in fact, they are a reasonable walk from the Ferry Building. If you feel like some exercise, walk north along the Embarcadero (in the direction of Pier 39) and take the Filbert Steps up Telegraph Hill to Coit Tower. Don't miss the little wooden alleyways off the steps (so many flowers!)
North Beach: there's a lot of touristy crap here, and it took Michael getting an apartment there for me to realize what a great place it is. Avoid Broadway as much as possible; Columbus has more of interest, but the side streets are the nicest, such as those around Telegraph Hill. My favorite pastimes there inevitably involved eating or drinking. We loved Cafe Trieste for our morning coffee, and Stella Pastry for deserts. Restaurants we enjoyed: the House (not Italian! They have Asian/Californian fusion small plates), Helmand (Afghan cuisine, including delicious squash dumplings), Osteria del Forno, Restorante Ideale, Albona Ristorante, Trattoria Contadina, and Tomaso's Pizza. (Our local paper had a roundup of the best pasta in North Beach). Cool bars in North Beach: 15 Romolo and Spec's/Adler.
One of my favorite bookstores is in North Beach as well: City Lights Books, which is something of a local historical monument.
Chinatown: My mother says she prefers going to Oakland Chinatown, because it's more purely functional and not overrun with tourists. However, the San Francisco one is definitely still more interesting to look at. (The Cultural Center offers walking tours.) Grant Street is the one filled with stores selling a lot of crap; walk up to Stockton to see the food stores where people actually shop. Not surprisingly, my favorite pastime here also involves eating. There are a some good dim sum places here: we like Gold Mountain on Broadway, Pearl City (Jackson, I think?), and City View (on Commercial).
If you like dim sum as much as I do, there are also excellent places further out like Ton Kiang and Mayflower in the Richmond district (kind of the new Chinatown) or at the very expensive but very tasty Yank Sing in the Rincon Center on Spear Street.
Shopping: Union Square is overrun with chain stores that you can find anywhere (though maybe cheaper than in London at the moment). If you want something different, then the best shopping 'hoods are the Castro (Cliff's Variety is really cool), the Marina, Fillmore Street, Union Street, and Haight Street.
Museums: San Francisco MOMA has good exhibits. I also really like the Legion of Honor (and the surrounding area is a nice place for a walk). Golden Gate Park used to have a bunch of museums but at the moment, they are all under construction...
Parks: Golden Gate Park is still pretty, despite the aforementioned construction. The Arboretum is a nice place to wander around. Afterwards, you can stop at the Canvas Cafe on Irving (and 9th, I think) — it's a cool cafe with art exhibits, live music, etc. If you're in the area around mealtime, Park Chow is a good and reasonably priced restaurant. Land's End is beautiful. If you're planning to do some bike riding across the bridge anyway, cycle around the Presidio too.
Touristy things: Fisherman's Wharf and Pier 39 don't have a huge amount to recommend them. Alcatraz is worth a visit, of course, but there's also Angel Island, which has a somewhat depressing history — it served as a detention center for immigrants from Asia (there's a museum there you can visit) — but is also a beautiful place to do some hiking. I think there's one tour that takes you to both places.
Further Afield
Yosemite is normally beautiful and untroubled by tourists this time of year. Unfortunately, winter seems to have started early, and you're not going to want to be on the roads or stuck in the mountains during a big storm. Check the weather forecasts carefully. Also, even at the best of times, it's a good four or even five hours away. You're probably going to want to stay for two nights.
If Yosemite doesn't work out, here's some other things I'd suggest:
1) Get up early in the morning and drive out to Stinson Beach (Highway 101 to Highway 1; hope you're not prone to carsickness!) Have breakfast at the Parkside Cafe and go for a walk along the beach. Then get back in your car and drive out to Point Reyes and go for a nice hike. Return to Highway 101 via Sir Francis Drake Boulevard, which is very pretty. Stop at Sausalito and wander around for a bit (you can also take the ferry to Sausalito from SF on another day if you prefer)
2) Drive up to Napa for the day and go wine-tasting, or just enjoy the scenery. It's also a good place for biking, I think. St. Helena is a very cute town, as is Calistoga. Or you could take 101 all the way up to Healdsberg, another cute town with wineries nearby.
3) Drive down the coast along Highway 1. You might want to allow a couple of days for this if you decide to go further than Santa Cruz. Stop at Princeton-by-the-Sea, Half Moon Bay, and/or Pescadero on the way down. Also, Ano Neuvo State Reserve has an elephant seal colony which is worth visiting, and I think this is a good time of year to do so.
You'll eventually get to Santa Cruz, my college town. Downtown Santa Cruz has great shopping these days, and the boardwalk is always kind of amusing if you like that sort of thing (check to see if it's open this time of year.) The beaches down here are lovely, especially in Aptos. West Cliff Drive is a nice place to walk along the coast.
If you're feeling really ambitious, you can get back in your car and drive down 1 to Monterey, which has a wonderful aquarium. I really like the neighboring town, Pacific Grove, which isn't as touristy and has the Asilomar State Beach Park. I have heard that you can take whalewatching trips from Monterey as well.
If you have more time and/or are staying overnight, try to get down to Big Sur. Amazing views, painful hiking. What more could you ask for? Nepenthe Restaurant is overpriced but still a very nice treat. If you want to be really really Californian, the Esalen Institute sometimes has rooms available to people who aren't enrolled in one of their seminars. They have the most amazing hot tubs perched on a dramatic cliff overlooking the ocean.
There, that should get you started!
More information
Bay Area Backroads: website of a local TV program on cool stuff to do and places to visit. Tons of articles here.
Best of the Bay: The San Francisco Bay Guardian's annual guide
Stanley Stephan's San Francisco Tip Sheet: By a member of foodie discussion board Chowhound.com. (These people are really obsessive about food, in a good way..)
