Here's a great book to look at to and study before going to Yosemite... The Photographer's Guide to Yosemite by Michael Frye. It's available on Amazon.com, and available as a used book. It's one of the best books I've come across re photographing Yosmite and has all sorts of tidbits about what to photograph, how to photograph, where to photograph, and the best time of year and time of day do it. Pretty cool.. and will get you excited about going to Yosemite!