St. Helena, CA is Napa's Main Street - it resides right in the middle of the Napa Valley with views north, of Mount St. Helena and the vineyards and south, to the town of Napa.
I chose a few places to visit in one afternoon, mainly because many tasting rooms or restaurants will make you want to stay for multiple tastings/courses, leading well into the night.. and weekend.
Food: On the patio at Velo Vino, you and your friends can kick back with a glass of wine and on Wednesday through Sunday 11:30AM – 6PM, you can grab a bite from their latest venture - Bruschetteria, their Italian style, quick bites food truck.. Even better: Every Thursday from 4pm – 7pm they host Happy Hour specials on select menu items - yup, 5 menu items for $5 each, along with wine specials for $5 a glass.
Drink: According to their website, Goose & Gander is "a wine country public house, a gathering place for locals and visitors to celebrate Napa Valley’s abundant bounty." This pretty much says it all - it is an outside, or inside bar that has some of the best cocktails in all of Napa Valley. I always recommend asking your bartender or serve what seasonal cocktails he/she recommends.
Fun: The Culinary Institute of America's "CIA at Greystone Experience" offer daily 30 minute tours of the historic Greystone building just north of downtown St Helena. They also have a dream shop for foodies, and three different restaurants. In order to take the 2:45pm tour, make sure to get there early to purchase on the day of the tour at The Spice Island Marketplace because tours ONLY will be on a first come, first serve basis on the day of your visit. Tickets are $10.00 per person (tax included).