What vegetables or herbs can I plant right now in San Francisco?

Not much. You are about to run out of growing season.

These can still be planted: Chives, Bunching Onions, Radishes, Broccoli, Leaf Lettuces, Mustard, Spinach. More info.

you might also be able to harvest a fall crop of peas

I know of an herb you can plant. Or you can just pick some up with a doctor’s prescription.

With your relatively cool climate and brief period of direct sunlight per day you will probably be most successful with cool weather plants. You can plant green onions, regular yellow or red onions, and garlic.

You might do OK with cabbage, Brussels sprouts or cauliflower.

Parsley will do well.

Rosemary is woody and hardy. It should do OK, but you need to let it dry out between waterings. Plant it in a place where it can stay. It will live for years.

The other common herbs thyme, sage, chervil, basil, etc. the ones that you use the leaves for seasoning, all are summer plants, started in the spring, so they won’t do well now. It’s too late in the season.

I planted herbs in a window box that last all through the NW year—although they were facing East. Oregano of different kinds, rosemary, thyme, chives come back each spring, sage. Also, I concur about the winter vegies, although I have never personally planted those.

try the advance search on http://plantfinder.sunset.com/sunset/plant-home.jsp

you can select herbs and your climate zone and get back information on planting and caring for them