North Coast CA- Check out Bolinas (right next to stinson beach), drive up Mt. Tamalpias (north of SF) where you can also take a walk through the redwood trees, the Klamath River is really great!
On your way to Yosemite- PLEASE check out the Underground Gardens in Fresno, CA http://www.roadtripamerica.com/places/forest.htm it is a funky, wonderful, awe inspiring place!!! One of the best small places to see. Engineers come from all over the world to see it.
Regarding Big Sur trip- the trip between Monterey and San Louis Obisbo is well worth the ride!!! Make sure you eat luch at one of the places in Big Sur that look out over the ocean. The coasts there is different from that of Northern CA. The coast between San louis Obisbo and LA you can skip- pretty but all the housing and traffic starts in that area. On your way inland from San Louis Obisbo check out the Madona Inn!