also try Peju Province winery, was there about a week ago and had a good experience, good deal with tasting fee being credited back with a purchase also. also a great place for images, very picturesque buildings and grounds...
would second the notion of trying NOT to see and travel too much in area of California or anywhere, lots to do and see within 50 miles of SF
I ran a few things through mapquest and skip the trip down the coast from Carmel/Monterey. Call it a day there and head back up. That gives you the ability to leave at 6am and get to Napa by 9-10am and have plenty of time to take things slow(I had to figure you'd stop and take pictures, so San Luis Obispo is out).
So the quick run through:
1 - down route 1 towards Santa Cruz and Carmel. Enjoy the food, the sights, and so on. Leave at 5-6am.(early) You want to reach Santa Cruz at about 9-10am.
2 - back up 2-3 hours on 101 and blow by the area and go to Napa. Yes, traffic will suck, but it's easily manageable to get to Napa before noon if you start early. Route 1 looks quicker, but it's not as there's no quick way to get from the 101 to Napa if you cross the Golden Gate Bridge and fighting downtown San Fransisco in the morning is insanity. Just head up towards San Jose and go towards Berkeley, then up towards Napa. Leave at 6am as well. You should hit heavy traffic at about 7am and be through it and in Napa by 8-9. Leaving at 8am means you get there at noon.
3 - Sonoma and Marin county.
4 - Downtown San Fransisco. Car optional on this one.
Don is right - within about 50-100 miles of San Fransisco, there's probably the best scenery in all of California in terms of easy access and speed of movement from place to place. You'll easily fill up your memory cards or have to buy more film