From San Francisco to Sonoma Valley:
Take US-101 north across the Golden Gate Bridge for 22 miles. Exit on CA-37 East towards Vallejo/Napa for 7 miles. Turn North on CA-121 towards Sonoma/Napa 6.5 miles. Stay straight on to CA-116 4 miles to Sonoma.

From Oakland or the East Bay to the Sonoma Valley:
Follow the directions to the Napa Valley; I-80 North to CA-37 toward Vallejo/Napa. Take the Marine World Parkway to a right turn on Sonoma Blvd/ CA-121, but you will turn left on CA-12 approximately 3 miles out of Vallejo. Follow CA-12 as it turns north and travels through Sonoma on its way to meet I-101 at Santa Rosa. 

From San Jose by car:
It's recommended you take I-880 North until it connects with I-80 at the East end of the Bay Bridge. Follow the directions above for Oakland/East Bay. 

Travel Times will very depending on the season and time of day. Avoid morning and evening rush hour if at all possible. Leave San Francisco or Oakland after 9:00am. Plan on about one hour from San Francisco or Oakland, two and one half hours from San Jose in light traffic.

Maps:
Travel maps for just about anywhere in the world can be found at Maps.com. In addition to travel maps you can find road maps, street maps, world maps and city maps and point to point directions.

You can also get detailed door-to-door, turn-by-turn directions at MapQuest.