I particularly liked "Photography" - (10th Edition) by Barbara London. (Apologies if this book has already been talked and/or posted about.)
It's a really great book, and I got it as a freshman in a photography college. It was a great introduction and I found the concepts were easy to understand and I really grasped on to the concepts fairly quickly. I'm sure there are newer versions of the book (I haven't checked.) I definitely recommend this book for anyone but personally as a beginner I found this been really great and amazingly helpful.