You're going to Napa? Here's some advice:
This is a great time to go to Napa. The harvest is just finished (it was late this year) and the crush is ongoing. The valley will smell of grapes. The leaves will all be red on the vines, and it will be cool (foggy) in the mornings. (I just came back from a trip to see some friends).
If you want to look at art visit Hess (up on Mt Veeder) or Clos Pegase (up by Calistoga).
www.hesscollection.com
www.clospegase.com
Look on the map and drive Silverado Trail; it parallels the main (tourist) road up the valley but's the one locals use. I prefer the view and the wineries on that side of the valley. Among my favorites are Silverado, which has a great view of the valle from their tasting room and some of my favorite wines (especially like their Zin), and Stag's Leap, which does some of the best Cabs in the world.
www.silveradovineyards.com www.cask23.com
On the other side of the valley go to Costantino's; they do small runs of dozens of good wines. They're known for the Cigar Zin, made to be drank with a good smoke. It'snot my favorite (I don't smoke) but I have some of his M Coz in the cellar; killer stuff.
www.cosentinowinery.com
One of my favorite weekend things to do was to drive up to Mumm's and have champagne for breakfast on Sundays. They have a great photography display of Ansel Adams stuff and another hall of new talent.
www.mummnapa.com
A lot of resturants change, but here are some of my favorites in the valley:
Celledon is really a locals place; it never gets the publicity of more trendy places but has some of the best food and service you'll find anywhere. I liked their old location better, but they have more room at the mill.
www.celadonnapa.com The same family also runs Cole's Chop House if you want the best steak in town.
Domaine Chandone has a great place too; it's about halfway up the valley in Yountville.
If you can get into Greystone it's usually good. I think it's pricy and prefer Celedon for fancy stuff.
If you have a date, absolutely take her to Auberge for dinner. Plan to be there about half an hour before sundown (remember the mountains) and you can get a specatular view as the valley lights up below you. Spendy but very good.
www.aubergedusoleil.com
Rutherford Grill is great for less formal stuff. It was one of my normal hangouts. Gets busy on weekends.
There's a brewery downtown on the river that's good too. Sit outside and have a beer. Also an Italian place off 39 that I can't remember the name of; it's been there for decades (look for the brick red building).
One of the best things you can do is picnic. Most wineries don't allow this, but some do. The best view I know of is from a winery up by Auberge del Sol. (I can't remeber the name). They will let you picnic if you only buy wine from them. Cheap at the price. Clos Pegase allows picnics. The old mill up by Calistoga does too, and has a nice park. (Problem is it's just past the high end shops, so unless you want to spend time shopping for stuff like Bose or Coach you have to be prepared.) Get the food at the local market. Then just drive up the valley.
If you really have time I suggest taking a drive from Napa to the Coast. Let me know if you need a route map; I did this a lot. It's a great Sunday thing.
Let me know if there's anything specific you have questions about. I lived in Napa for 5 years, and in the southern part of the bay almost as long. If there's anthing you want to see (scenery, ocean drive, museums, aircraft, cars, expensive shopping ares...etc) just let me know.