After NHC last year we spent a few nights at the El Bonita Motel in St. Helena as a base camp for touring wine country - nothing fancy, but we spent most of the day touring around wineries (2 or 3 per day was just right - pick your favorites).
http://www.elbonita.com/We dined at Downtown Joes, Mustard's Grill, Pizzeria Tra Vinge.
There is an excellent bakery in St. Helena that we would start our mornings at, The Model Bakery - we are not big breakfast people.
On Wednesdays they close off the street in front of Russian River in Santa Rosa and they have a street fair / farmers' market - that was fun and different. I went through the tasting plate at RR while my wife checked out the stalls at the street fair.
There is a small brewery at the north end of Napa Valley - Calistoga Brewery - if you do not want to drive over the mountain another 45 minutes to Russian River. And Downtown Joes is at the opposite end in Napa.
One of my favorite restaurant's in the city is A16
