One of the best things I was able to do when living in the Bay Area was being able to go to Yosemite fairly easily. It was about a 4 hour drive and there were a lot of shuttles than ran from SF to the park. Due to that, I probably went 4-5 times one summer a lone. Below are a few pictures I took on those occasions. My best advice to visit Yosemite is to take one of those shuttles or even a tour bus. Once in the park, rent a bicycle and ride around the park. It is by far the easiest, and most enjoyable, to try to see everything. Like any outdoorsy type trip, bringing lots of snacks and water is a must!
The famous half dome. I was lucky enough to see some climbers on the face of the mountain.
LazySeoul's Adventures 