If you're on a budget, Sonoma is FAR more cost-effective than Napa. It's also much more diverse in terms of microclimates, and wine varieties.

Russian River area is for cool varietals like Pinot Noir, Chardonnay, and sparkling wine made from those grapes, with some Zinfandels as well. Some of my favorite wineries here are Hartford, Martinelli, DeLoach, Gary Farrell, and Hop Kiln. Rochioli is a great winery, that is invariably sold out of most of their wines.

Dry Creek is the Zinfandel capital of the world. I really like Rafanelli, Quivera, Ridge, and Mazzoco

Alexander Valley is for Cabernet and Merlots. and some Zinfandel. Wineries to see are Simi, Sausal, Field Stone, and Alexander Valley Vineyards

Rhone varietals do well in a range of climates and can be found in all of these regions.

As far as hotels, Sonoma/Santa Rosa is less pricey than Napa, and weekdays are substantially less pricey than weekends. You can often get the Hilton or Doubletree in Santa Rosa or Rohnert Park for under $75 a night on Priceine during weekdays. Friday and Saturday nights, you can expect to pay MUCH more.