Get OrientedThe Napa Valley runs from the town of Napa in the south to Calistoga in the north, less than thirty miles. If you're going to do it in a day, it will help if you know the layout. Use the Napa/Sonoma Map to figure out where everything is.
Pace YourselfWe've been on enough winery tours and visited enough tasting rooms to tell you with authority that most of them are more or less the same. Everyone makes wine the same way, and unless you're a wine connoisseur, it all tastes nice. The most interesting tours and prettiest tasting rooms are off the beaten path, and you're not likely to find them by just driving into Napa Valley and picking a place at random.
Furthermore, a visit to Napa is about savoring what it has to offer, not speed-drinking. Rather than packing in a bunch of winery visits in one day, pick one winery tour and one wine tasting from our top Napa Valley wineries list, going to one in the morning and one in the afternoon. The best will require reservations and it's essential to plan ahead.
Depending on the wineries you've chosen, drive through Napa Valley on Highway 29 in one direction and on Silverado Trail in the other. Not only is Silverado Trail less busy than the main highway, but it's more scenic, too.
The patio at Domaine Carneros south of the town of Napa on CA Hwy 121 is a great place to end your day in wine country. They're open a little later than other wineries and the views from their patio are extraordinary.
DiningAllow enough time for lunch in one of the Napa Valley's many fine restaurants. Centrally located St. Helena may be the most convenient place, and you'll find a nice selection of excellent eateries there.
For an easy wine country picnic, buy some goodies from Oakville Grocery (CA Hwy 29 at Oakville Cross Road) or the Sunshine Market on the south side of St. Helena. Our Napa Valley winery guide lists some of the best places to picnic.
Getting to Napa ValleyIt will take about an hour to get to the south end of Napa Valley from San Francisco. Use this guide to find out all the ways to get from San Francisco to Napa Valley.
If you only have a day, getting stuck in traffic is not the way to spend it. Check the car racing schedule at Sonoma Raceway and if there's a big race going on, it will be faster to take I-80 north and CA Hwy 12 west to get to Napa Valley.
If you're taking our advice to skip the rental car while staying in San Francisco, you can rent one for the day from Avis or Hertz's city offices near Fisherman's Wharf or Union Square.