If you're flying into Northern California to visit Sonoma County or Napa Valley, rather than landing in San Francisco or Sacramento, consider flying directly into wine country. There are plenty of flights into the Sonoma County Airport (STS).
Here's the current list from the Petaluma Argus-Courier. This information is also at the airport's site.
Approximate drive times from STS:
Healdsburg 13 minutes
Sonoma 50 minutes
Calistoga 32 minutes
Napa 65 minutes
