In SF, Tadich Grill and get the cioppino. If you're going to be at Fisherman's, walk a little west and eat at Buena Vista Cafe. Greatest bread pudding and claim to have "invented" the Irish Coffee. In the Mission, get a burrito at El Farolito. These are all well-known, easy places to find though maybe not adventurous. Fantastic food, tho. If you end up in the Financial District, may as well walk to Ferry Building esp. on a Tuesday, Thursday or Saturday for the Farmer's Market; quite a few small purveyors with great stuff (4505 Meats for a great burger). Depending on the day, rub shoulders with office drones or frou frou yuppies. Again, fantastic food.
SF is chockablock with food. East Bay is also amazing (and better value), but would require coming across the bridge.
The bread you mention was probably referring to sour dough bread (e.g., Boudin Bakery).