I have just read The Photographer’s Eye by Michael Freeman - it is amazing book. I would advise to read it everybody who is interest in photography composition, is not professional and has not studied arts (like me) - it explains the basics of composition in a simple way. The language use is simple, easy to understand. These are the things I lacked in my knowledge. All descriptions are visually explained which the descriptions much more useful. After reading it sometimes I started analyzing pictures of good photographers' - in pictures you can actually see those basics of compositions you would never think of if not knowing those basics.
Though I should confess that this is a first book I have read about photography (other than various tips in interent).