This little book is a gem. A couple of reviews here are too hard on this a 125 page tour. I came to this book as somewhat of a philosophy novice unlike, it seems, a couple of the disappointed reviewers here, so my perspective may be naïve, but the book did it's job for me and then some. Early on Craig correctly recommends reading slowly, because he packs a lot into the short tour. Apologies to a previous reviewer who found it shallow, keep in mind it's a large task for a small book.
If you know nothing of philosophy, I'd recommend first, as Craig does also, Thomas Nagel's "What Does It All Mean". My first read was Bertrand Russell's "History of Western Philosophy" which was too much for a beginner, although it did give me a sense of the history of western thought as it was intended. Russell's "The Problems of Philosophy" would have been a better start, but Russell can be a bit technical for the beginner.
Craig's book is not so much an intro to the problems of philosophy as a whirlwind tour of the major ideas that encompass western (and some eastern) thought, beginning with Plato, jumping to Hume and touching on some of the authors favorites: Descartes, Hegel, Nietzsche, and the impact of Darwin. He discusses some themes and introduces some "isms". He recommends readings along the way, and the end provides a list of other recommended intro and intermediate texts. He wraps it up with a chapter titled, "What's in it for whom": The individual; The priesthood; The working class; Women; Animals.
Craig did an excellent job piquing my interest in further readings. His enthusiasm for the subject matter is obvious.