newbie neding help- California trip
LA to SF is 617 km (1 to 2 days), SF to Yosemite is 294 km (1/2 day) with 2 steep grades, Yosemite to Death Valley is 498 km (1 day) with 4 steep grades, DV to Las Vegas is 226 km (1/2 day), LV to Grand Canyon is 445 km (1 day) with 2 steep grades and GC back to LA is 787 km (2 days) with 4 steep grades. Total is 2867 km, estimated driving time is 33 hours. So you will probably be driving part or all of 8 days of the trip. It can be done, but you will probably be spending only 1 to 2 days in each place. Plan to spend the first day recovering from your flight rather than driving... Save seeing LA for last so you are back there a day or two early; this provides you a buffer for the unexpected.
Keeping kids occupied while driving may be a challange. See if the unit you are renting has VHS or DVD which will work while you are driving (if the TV is visible to the driver, it won't work) and if not, consider buying a portable unit. With a stock of movies, of course. Games, coloring books, puzzles, etc as well. Not sure if they will enjoy Las Vegas as much as an adult would, as many of the attractions are age limited.
You may want to consider signing up with Passport America, and get 50% off at participating campgrounds. Good Sam Club has a small discount at some other campgrounds (10% I think), Gas (at Love's) and offers the free travel routing service I used to provide the above mileage info.
For the Grand Canyon, if you go on your own, you will likely not be a happy camper due to the lines, crowds and restrictions. Marvelous Marv has a great tour which gets around most of that and if you make your reservations though the adequate campground (which is a Passport America member) he is affiliated with (Canyon Gateway, in Williams), the price is not too bad. Williams is also where the train to the Grand Canyon comes from, if that is your preferance.