In reply to colina:
Of the campsites in The Valley itself we chose Upper Pines - great location near Curry Village for any shopping requirements and cheap dinners. There are no electric hook ups but I think that's true of all campsites in the park. You may find you're too late by now to book a site at one of the valley sites. If so try Crane Flat campground - just outside the valley on the way to Tuolomne Meadows - and there's a beautiful sequoia grove within walking distance.
Don't miss Tuolomne Meadows - beautiful place with great walking, valley or High Sierra summits.
We meant to camp high and walk Half Dome at a leisurely pace over a day and a half. In the end we couldn't get a camping permit and did it in the day from the Upper Pines Campsite. We found a good tip for the route in, surprisingly, The Lonely Planet guide - this involves leaving the main path (trail they call it!) fairly soon and diverting up a section of The John Muir Trail. Then do the main path (trail!) on the decent - highly recommended.
Others will have more suggestions I'm sure.
At South Lake Tahoe we stayed here
http://www.recreation.gov/camping/fallen-leaf-campground/r/campgroundDetail...
It proved to be a lucky choice - I believe the Lakeside sites can be a bit "holidayfied" if you know what I mean. Fallen leaf is quiet and pleasant, or was when we were there.
Can't help re walking around there - we just went climbing at Lover's Leap which is brilliant.
