Practical info:

• Located at 100 Alemany Boulevard, in San Francisco. Google Map * Yahoo Map
• Driving directions: Take 101 South to the Cesar Chavez exit. Bear Left for CC East/Bayshore, and then again bear right for Bayshore Blvd. Continue down to Alemany Blvd and turn right. You'll see the market on your right. Either wait an eternity for parking to open up in the market, or drive around the neighborhood for plenty of residential parking.
• Hours: every Saturday, 6am - 5pm, year round
• Temperature: This is San Francisco, so even on sunny days, you might want to dress warm.
• Types of produce: One stand has an excellent selection of common and exotic mushrooms (including pink "flamingo" oyster mushrooms). Several specialize in Asian vegetables like bitter melon and bok choy, and even some with Asian herbs like "hot mint" and Thai basil. Lots that have a large selection of Western vegetables and fruits. There were a couple of very popular Filipino stands with vegetables I didn't know. Also a few stands selling live seafood (crabs for $4.50/lb, shrimp) and a cheese stand.
• Ready to eat stands: They have a couple of bakeries (bread & pastries), 1 Mexican brunch food stand (with tamales & chiliaquiles), 1 specializing in Afghan food, another in Indian food (with ready-to-eat samosas), and 1 crepe stand (see picture below at bottom). The crepes were $4-8 apiece, considerably cheaper than Ti Couz and freshly made.
• Prices: Vary based on season. We bought Swiss chard at $1/bunch, compared to $2.75/bunch at the Oakland Splash Pad Park market, but the quality wasn't as good. We bought 3 cartons of strawberries for $5--excellent quality but not organic (they sold out of those by 8am). We got beautiful portobello mushrooms for $4/lb. A GREAT salad stand was selling mixed greens, arugula, mizuna and others for $2/lb.