As an ex resident of California, I've never done a actual roadtrip but there's some great advice on here, but a few more things off the top of my head.....
* If you're not adverse to "camping" (it's really not camping) then check out Autocamp both in Russian River and Yosemite
Luxury glamping in iconic outdoor destinations! Visit us in Joshua Tree, Russian River, Yosemite, Sequoia, Zion, Catskills, Asheville, Hill Country & Cape Cod.
* Assuming you'll be visiting SF, then be very careful about hotels. Most tourists stay around Union Square, which is bordered by the Tenderloin the cities biggest ghetto with a great deal of deprivation and drug use. If your budget will stretch then one of the Nob Hill hotels like Fairmount or Mark Hopkins then do so, otherwise there's other hotels that I can recommend that are a little out of the tourist traps.
* On the subject of homelessness, you'll need to get used to it wherever you go in CA as well as open use of hard drugs on the streets
* Give me a shout before you go to SF and I can give you much more info about exploring the city, it's not huge and living there for 4 years means you know it well and so happy to do a detailed post about places to eat, drink etc
* Depending on when you go to SF it will be either cold, or freezing, in at least one area - unless you get there for the 3 week summer which is normally around October. Also take a coat / jacket wherever you go, as just because it's sunny in the FiDi doesn't mean it'll be sunny when you get to the Outer Sunset a distance of a whole 3 or 4 miles. There's microclimates across the city, which you get used to.
* You say "west coast" but everyone is focusing on CA, Oregon and Washington states are also amazing, especially Portland and Seattle, but I wouldn't recommend driving down to CA from OR as there's not a great deal between say Portland and San Francisco.
* If you like wine, or even if you dont, then Napa and Sonoma valleys are great places to explore a few days, really relaxing and there's some great hotels I can recommend (although pricey)
* Stick to the Pacific Coast Highway when driving from SF to LA, there's some great towns to check out like Santa Barbara, Monterey, Carmel, SLO which you'll miss if you take the I-5-S which is the most direct route, and has a great deal of nothing through the central valley.
* I can probably give you hotel and restaurant recommendations for most places, as we used our time in CA to explore a lot so just shout.