I have to tell you that I would avoid the California border to San Francisco altogether if possible. While it's certainly beautiful the drivers are absolutely murderous.
While riding VERY early in the morning on the northern Highway 1 I've had completely straight road with good visability and totally empty road both directions and had logging truck pass LITERALLY within inches of me.
Now every year hundreds if not thousands of cyclists ride this route without incident so perhaps I'm being overly sensitive but I've never felt like that south of San Francisco.
But if I were doing the ride at the Oregon-California border I'd cut inland and head for Highway 3 which is REALLY scenic. It ends at Whiskeytown and there are a lot of roads you can take there to move south ending up in Clear Lake and then traveling from there to Vallejo and into Richmond where I'd take the BART to San Francisco and then go south on Highway 1 again.
The advantage of these roads is that they are pretty empty of heavy traffic, they have a lot more open land - certainly there are areas in which you can ride for hours without seeing a car or a speeding motorcyle. And you would be doing your OWN tour and not someone else's.
If you join the American Automobile Association (AAA) you can get free road maps at any office or have them sent to you for a reasonable fee.
There are a ton of roads in California, unlike many other states this side of the Mississippi which have few roads other than the main routes. Even on the worst routes there are spectacular scenary and memorable sections. Oregon and Washington are the same actually.
The Pacific Highway is a tried and true trip but it also runs along some of the most heavily traveled tourist routes in the three states. Well, not so heavy in Washington and Oregon but up there it may rain the entire time you're there.