Ok here is top tips from our trip last summer.
SF fantastic, we did airbnb house, easy to get around on buses.
didnt bother with Alcatraz, cant see the point its just a prison with stories of unpleasant people.
DO PLEASE GO to the Exploratorium just along the wharf from the alcatraz tourist hell. Its amazing and can easily fill a whole day, infact you wont get the kids out of there and A LOT more fun than the queues for Alcatraz. It was the highlight of SF for my 9 and 10 year olds.
Hire a bike and go over the bridge to sausolito get lunch and ferry back.
Have dinner at all the food trucks on 'Off the Grid'.
Take jumpers and coats, IT GETS COLD in the summer fog.
Go to the Montery bay Aquarium and book the kids in for a Scuba dive as a surprise and you will be a Hero!
Its in dry suits with instructors, they get to dive in an open sea reef pool built into the aquarium. A-maze-ing.
Book a boat trip to go whale watching anywhere along the coast, but Montery has plenty to choose from. Top tip go for the bigger boats with indoor cabin as I said before IT GETS COLD IN THE FOG!!!!
Stop off just north of Cambria to see the Elephant seals on the beach, they stink to high heaven.
Yosemite is fantastic, really well organized routes, vistor centre etc. We stayed outside the park at Mariposa.
If you want to do Las vegas, Hoover dam etc its a lot of driving, with kids, in the car, for hours....Hire the biggest car you can so they don't even have to hear each others breath and get fully stocked up on apple gadgets, then be dissapointed that they missed all the amazing views as they played Mine craft. But the Grand Canyon will take your breath away, loads of Motels in Williams and the closest you can get in high summer, but still a 90 min drive away.
I booked up most nights and spaced out the driving to no more than 8 hours tops, but it is a lot of time in the car.
I would do it all again in a flash. Best hotel the Saguaro Palm springs, absolute paradise!!!