I used to live in Santa Barbara and can recommend the following five, no-appointment-necessary wineries without reservation:
Melville (for chardonnay and pinot noir);
Blackjack Ranch (often overlooked, but they make some of the very best wines in the area);
Andrew Murray (syrah);
Curtis (next to Firestone; great cost-to-quality ratio); and
Jaffurs (fantastic syrah; in downtown SB).
Beckman has also been turning out some nice Rhone varietals, including their grenache. Longoria makes a good cabernet franc. And Consilience has an excellent petite sirah (though its syrahs are way over the top, IMHO). And I happen to like Sunstone, simply because it was the first winery I ever went to -- and because it's really beautiful. Also, it's right next to Kalyra, which makes some decent dessert wines.
I'd skip Gainey, Firestone (although, if you do go to Curtis, you'll be able to use your tasting glass there, but only head over if you have lots of extra time), and Epiphany.
Some good wine shops in Santa Barbara are Lazy Acres (on the Mesa in SB), East Beach Wine, and the Wine Cask (which has tastings of Doug Margerum's very decent wines, including M5).
Have a great time!
Michael