Good info so far. First off, go to SFO. Its a little south of the city but will give you the choice of visiting SF either before or after and going over the golden gate is a must if you haven't don't so. Forget Oakland, yes it may be cheaper but less scenic and you're on vacation so at least be accessible to SF if you have the time. If you're not totally set on spending your whole time up in wine country, I'd definitely spend a day in SF. Ride the cable cars, drive down lombard st, etc etc if you haven't done so.
When you guys decided Napa, I'm assuming it was for visiting wineries primarily. Lots of good restaurants there with nice lodging all really depend on what you're budgeting. Like Ted mentions, unlike the days of old, most wine tastings cost anywhere from $10 and up with some library tastings north of $75. If there are any specific wineries you want to visit, make sure you check to see if you need to make a reservation or appt, and if they're even open to the public now require that (you can always make them day of but you don't want to be disappointed just in case), and be aware of any tasting costs. Being in the industry always helps as tastings are free and with most wineries you get a decent discount. Sonoma is more accessible and less "grand" if you will and they're more Chard/Pinot whereas Napa is heavily Cab.
We always stay at the Carneros Inn as they're in between Napa and Sonoma and you get your own little cottage if you will. We love the Boon Fly Cafe and Farm which are both on site. It is on the higher side so if you like you say, if you want to go economical for your stay, that may not be the place but if you're going out there, I say why not. There are many b&b's up there and since you'll have a car, everything is a drivable distance up there.
And the Fremont Diner, even if you're not staying there, is a great place for fantastic home cooked breakfast and lunch. Yountville has the French Laundry as well as Ad Hoc which are both T Kellar's places. If you want to do the French Laundry though, make reservations well (I mean like 1 month minimum) in advance. I agree with Ted on Healdsburg. Fun town and I had one of my most memorable meals at Cyrus. There are actually a couple of smaller inns right in the town square there. G1
