Larry be sure and check out the Tasadi (sp) cabins. They are up that way and seem to be pretty nice.
It will be busy that week with the 4th of July and all. Shasta is huge though and you can almost always find good water.
We have three kids ourselves so the campground works good for us. There is a pool and a little store. They also play a movie every night for the kids to watch. Family orientated campground.
By far the best time for Shasta is in Sept. A longer walk to the boat since the water level is lower but the lake is dead.
It would be cool if you could make the trip we have meet so many people from WakeWorld. Some of them have become really close friends of ours. Great people. http://www.shastacounty.com/shastalake/