When you fly into San Francisco, you will encounter a city full of adventure that is less than an hour away from gorgeous countryside and vineyards. You can take one of the bridges out of town- the Bay or Golden Gate bridges. Less than an hour will take you to either Sonoma or Napa cities. Both are located on the south end of their valleys which lead to more small cities and multiple wineries. Before you get to either city, just to the south, you will pass through los Carneros which is a cooler spot used to grow very good Pinot Noir, Pinot Meunier, and Chardonnay. All valleys grow high quality grapes, though Napa holds slightly more history and prestige.
In the center of it all is Sonoma city. By traveling east you can reach Napa city and take the highway north between the mountains, up the valley, and through the cities of Oakville, Yountville, St. Helena, and Calistoga. Traveling west of Sonoma, you drive past Petaluma and north through Sonoma county up to Santa Rosa and Healdsburg. And just to the north of Sonoma is Kenwood and Glen Ellyn. Every one of these small towns has something great to offer- including many wineries very close by! Plus each city, and the beach, are less than an hour from Sonoma. It seems most who live here have no need to travel elsewhere, but don't get complacent as this, and the world, has much more to offer.
Make sure you have a good map or GPS available. Even though it is easy to manuever, it is easy to get lost as well. Also, prep clothing for multiple climates. The bay area can be a bit cooler and the valleys a bit hotter. San Francisco is currently about 75°F and the valleys 95°F. And if you buy wine, remember you can no longer transport it in carry-on luggage. Be prepared to either check wine carrying luggage or ship it.