Back in 2013 we stayed at
Yosemite Pines in Groveland, CA and found it to be a very nice stay though it does take about an hour to drive into the park central where the shuttles are available. We also visited in May and found the park very nice and all of the falls flowing profusely. Allow a few days as there is much to see. Don't forget to take a trip to Hetch-Hetchy which is an almost duplicate of Yosemite though it is just a lake providing water to the San Francisco area - a lot of history there!!
Also be sure to drive up to Tuolumne Meadows on a day trip. It is magnificent in May and there will still be snow in places as well as fantastic views along the the way through Tioga Pass.
Our write up of that stay is located
here on our blog.