Traveling to California this summer

Yosemite valley is very crowded, you will need reservations, other wise you will be camping in the park, but not in the valley

Personally Kings Canyon / Sequoia is my favorite park

As long as your coming to Calif, first go into Utah to Arches National Monument, and Capitol Reef park, and Bryce Canyon

Then come down into Calif

Kings Canyon and Sequoia NPs are somewhat similar, yet different. Both have magnificent groves of Sequoia Redwoods. I would choose Sequoia first.
If you are planning on this summer, I would make sure I have reservations at an RV park close to Yosemite and Sequoia far in advance. Like right now!
When you travel north, you will go through some spectacular Coastal Redwoods. The difference between the Sequoias and Coastal is that the Coastal are tall, while the Sequoias are larger around. Both are very tall and with huge girth, however.
You don't say if you have a toad or not. If not, you will have to arrange transportation to the parks. I doubt very much that you could get a RV space in Sequoia or Kings. You will not in Yosemite. A consideration.
I would go north from Yosemite/Sequoia on CA-99 to I-5, to Lodi, take CA-12 through Sonoma to Santa Rosa. My reasoning is that going through Sonoma is worth stopping, even if just for lunch at one of the restaurants in the square and seeing the northernmost Calif. Mission. Also in the Valley of the Moon is Jack London's home.
From Santa Rosa north, you will get into the redwoods and see other attractions.
An alternate way, if you don't want to go through Sonoma, is to take 12 to I-80, jog south to CA 37 (which is about 5 miles) and take it to Lakeville Road, which will take you to 101 in Petaluma.
Any way you go is really pretty country.
Have fun!

After Yosemite, I would highly suggest getting on Hwy 101 from Napa and taking it all the way up into Washington. It's a beautiful, RV-friendly drive and you'll see plenty of huge redwoods. Ancient Redwoods in Redcrest is an excellent place to explore the big trees. Have a great trip!

I live in Southern California... But sounds like your on the right track... Any thing inland could easily be 90 - 100 degree F. I'd say stick to the coast or the mountains.... on your way to Oregon.... Anything past Sacremento is pretty nice in my opinion.... You could always consult your local Auto Club they have the whole state by state thing available for planning a trip and sights to see....

Mike C.