I highly recomend How to Play the Chess Openings by IA Horowitz. This is a first book on openings for a player who knows the moves but not much more. It explains the ideas of center control and tempo. It has some brief discussion on several of the most popular openings and their general goals. It then has several example games annotated for each opening. I used to coach chess and regularly recomended this to my pupils.

http://www.amazon.com/exec/obidos/tg...s&n=507846