Not an exhaustive list of places to go around Napa and Sonoma Valleys because, you know, there are 1700 wineries there. So, here are just a handful of suggestions:

Wineries

Hall
Stags Leap
Cline

Experiences

Napa
- Napa Valley Wine Train
- Oxbow Public Market
St Helena
- Gott's Roadside - Great place for a burger // There is one at Oxbow too, but the St Helena one has a grassy outdoor area with picnic tables
Yountville
- V Marketplace
- Bottega - Owned by one of my favorite chefs of all time, Michael Chiarello