Yosemite is arguably the most beautiful places on earth. I have been then tens of times, and never tire of visiting the park. While the Valley floor can be crowded, it’s still worth visiting. For a first time visitor to Yosemite I would recommend staying in the valley if possible. Lodging options range from camping, to tent cabins in Curry Village, to a couple of very nice National Park Lodges. I would recommend spending at least four days in Yosemite. If you like backpacking, I have a collection of links about Yosemite on my Camping / backpacking Destinations page. Yosemite Valley is around 4 hour drive for the Bay Area. A possible schedule might looks something like:
Day 1: Circle the Valley – would recommend a combination of using the free shuttle and walking… or consider using a bicycle you have brought or rent by Curry Village. It is possible to drive around the Valley, but this is discouraged by park officials.
Day 2: Drive toward Wawona. Make sure to stop at the look out just before the tunnel. Continue on to Mariposa Grove and see the huge redwood. There are a number of nice day hikes around the south west corner of the park. Stop at Glacier Point to see the sun go down and hear one of the ranger talks.
Day 3: Take a hike. People who want to push themselves hike Half Dome.. but there are lots of other wonderful hikes.
Day 4: Head up to Tuolumne Meadows. See the high alpine landscape. Take a hike.
If you have the time, cross Tioga pass and head down to check out Mono lake and the area around Devil’s Postpile. On the way to Devil’s Postpile you will past through the nice community of Mammoth Lakes. The food at the Convict Lake Lodge is quite tasty.