I did the trip from Calgary down through to San Francisco last spring. Two of us drove non-stop and looking back I kinda regret that. We missed some of the good stuff while driving at night. One thing I would recommend from my experience is to take 101 along the coast for one direction of your trip. Not as fast as the interstate, but much better scenery.
Also, I am not sure if you are to interested in tech stuff, but I had friends who work in Silicon Valley, and getting a tour of some of the facilities was pretty interesting. We also did some of the tourist things like Alcatraz.