I've rented in Sacramento (Executive Flyers) and flown a bit of this route north of San Francisco as far as Fort Bragg - wonderful.
Also rented from a small outfit in Petaluma with instructor and done the SF Bay Tour.
Both well worth the modest cost.
Have driven the route north from SF a few times, again - wonderful. Surprisingly deserted for the most part - if you're used to crowded, commercialised scenery in the UK.