Discovering Chess Openings by John Emms
In Discovering Chess Openings John Emms argues that studying openings doesn't have to be hard work - it can be both enjoyable and enlightening. The key to successful opening play is not simply learning lines off by heart; instead it's the understanding of the basic principles, and here the reader is guided through the vital themes: swift development, central control and king safety.
Discovering Chess Openings: Building Opening Skills from Basic Principles
Understanding the Chess Openings by Sam Collins