I have two links to share - the Destination Highways Books are excellent. There are 3 - British Columbia, Washington and latest one is Northern California. They seem a bit expensive at first but they save hours of trying to find those perfect secondary roads and are fun to read. I have used the BC and Washington ones. I have not been into Northern California yet but the book is providing hours of day dreaming. They have videos of some of the rides on their site.
The second link is useful for anyone planning a ride in British Columbia and the western part of Alberta - shows distances in kilometers and saves any USA riders the conversion from miles. The Kootenays in BC are amazing and very motorcycle friendly. Most drivers will pull over to let a bike by as soon as you show up in their mirrors.
I've used Destination Highways Washington, and have ridden a few of the highest rated roads they have listed... many, MANY more roads to try. Lots of daydreaming and trip planning too!
Excellent guide, very informative! Some of the online videos are great too!