This is a beautiful section of Tuolumne County, the visitor's bureau will have plenty of contacts for you. www.TCVB.com. You might look at home or condo rentals.
Have a marvelous trip!
We recommend both Pinecrest Lake Resort and Pinecrest Chalet. Pinecrest Chalet is further from the lake but has some very nice 2 bedroom condos; a nice swimming pool; play equipment for the children; barbecue areas; lots of picnic areas; and is a nice place to be away from all the people at the lake. Its about a 5-10 minute drive to the lake where you can go fishing, swimming, and just hang.
Pinecrest Lake Resort is closer to the lake and easier to just walk to and from the lake.
Book now as the place gets quite busy in August. If you don't mind driving to the lake, I'd book at Pincrest Chalet since its a fun play for families (and not as much road traffic to be concerned about.) Enjoy your trip!