I second the Schaffer book...my first hiking book ever! On my third copy...this book got me excited about hiking in Yosemite just by reading it! Planned my first backpacking trips ever using this book. Very descriptive.
I have hiked & backpacked quite a few of the trails found in the book and found the descriptions to be accurate and easy to follow. Trails vary from easy to very strenuous (something for everybody).