We spent the July 4 weekend at the Olema Campground near Point Reyes. We usually camp in somewhat primitive condition and this was the most upscale experience we have had so far. I really recommend it for families especially for families without much camping experience. The tent sites are pleasant and the resort has many conveniences: hot showers, a little store, laundry. There's even a playground for children. The campground is very close to Point Reyes National Seashore, so many activities are possible there.
Here's a picture of the playground:
Here's a picture of the playground: