I have a few knitting books. Stitch N Bitch, The Encyclopedia of Knitting, Knitting for Dummies, Teach Yourself Visually Knitting, and Cool Stuff: Teach Me to Knit (kids knitting book).
The one that I find the most useful is the Teach Yourself Visually Knitting one. The pictures are large and colorful and the directions are easy to follow. I used it the other day to learn how to do cables. I also got a lot out of the Cool Stuff book as it's geared to kids and was easy to use. It has several simple projects to work your way through to get your skills up.