EWOLD is definitely the guide to have on LD in general, it's almost like a bible to most people.It was my first book on the topic and I thoroughly enjoyed it and can recommend it wholeheartedly for a beginner like myself.

Alternatively, there's another great book that I've bought in the last week, that, dare I say it, slightly surpasses EWOLD in it's overall content and it's called "Lucid Dreaming - Gateway to the Inner Self" by Robert Waggoner. This I think is more for experienced Lucid Dreamers, for it delves more deeply into the meaning of dreams, how they sometimes conjure up things from subconscious that can still surprise us with their apparently insightful knowledge of our waking selves.