Fresh from my trip to California...okay, not exactly fresh, I am jet lagged... I have come up with three things I think you should experinece while you are in Napa.
1) Visit the Martini House....They have it all, great food, wine and activities. It is a fabulous time. www.martinihouse.com
2) The best place to experience the gorgeous sunset and have a tremendous drink is Auberge du Soleil Restaurant. You will have to go off the Silverado Trail and spend a pretty penny, but it is well worth it. http://www.aubergedusoleil.com/
3) Go to Oakville Grocery, pick up a sandwich and picnic in the valley. http://www.oakvillegrocery.com/default.php
Also, for something different and laid back, visit Taylor's Refresher...Best Gourmet Burgers and a chance to catch up with some locals. http://www.taylorsrefresher.com/menu/index.htm