Sonoma and Mendocino counties are the heart of the Red Triangle. Bring your best 5 mil chainmail Sharkproof wetsuit. SF isn't too bad, but you won't be warmly welcomed by the locals at the popular spots (under the Golden Gate or a couple of rocky points), and you better bring your paddling A-game if you wanna rock up to OBSF. If you're a relative novice, there's always Linda Mar...but it has a reputation for being the "kook spot" in the area. Lots of long soft tops and arbitrarily bailed boards in the lineup.
If you're looking for strong, consistent NorCal surf, Sonoma County fer sure. However, re-read the above about Whitey. Many incidents in this particular stretch. But there is some azzkicking surf when all the conditions come together.
Your best bet? Drive the extra distance south to Santa Cruz. More crowds, but the surf can't be compared. Many world class points, reefs and beachies on both the West and East sides. Be aware: most of the surfing in this area is also high caliber and the crowds can be aggressive. It can be difficult to catch a wave here.