Just before heading to Carnage 12 I finished reading another Richard Dawkins book I got last Christmas, The Blind Watchmaker, but I'm only just getting around to reviewing it (despite posting one article about it already).
In a way, The Blind Watchmaker is a better book to be someone's first Dawkins book than the others I've read, The Selfish Gene and The Extended Phenotype, for the very reasons it was less compelling to me. It's more targeted at the reader who has given very little thought to evolution and what it means, and more focused on a string of counter-arguments to the various misimpressions and criticisms of evolution than it is on any coherent exploration of any particular topic.
Dawkins posits it as a discussion on the common theme of how evolution is not random, despite the misimpression people have gotten from the inclusion of the random factor of mutation, and therefore, how the evidence clearly supports evolution. But my feeling on reading the book is that it's more of a hodgepodge of chapters addressing one and then another counterargument, along with lots of explanation and supporting evidence, which build up a fairly good case for the person whose knowledge of evolution is limited to the half-baked impression they got in eighth grade science class plus the spoon-fed factoids in the media. In the process it never quite gels into a structured argument made step-by-step. There was never a moment when I felt like we'd reached a conclusion.
For someone who hasn't thought all this through, who is willing to believe in evolution or who does believe in it but doesn't really understand it, this book would probably give more of a sense of coherence because of the sheer power of its many arguments and examples. It would arm them with a much more firm understanding of a lot of the most poorly-understood things about evolution which would in turn give them the arsenal to counter the ill-informed criticisms made by the opposition.
For instance, quite a lot of the book addresses, from different angles, the (to my mind odd) assertion that the eye is an example of something that couldn't evolve by a series of individually valuable steps, because it's too complex. (This one has always seemed especially odd because pretty much every intermediate step from photosensitive single-celled organisms on up still exists in the world. Wings seem a better point to argue about, not that they're a good counterargument or anything, but at least I could see where you're coming from.)
As with the other Dawkins books I've read, this one is chock full of interesting and fascinating stories about the natural world, which are enough reason to read it on their own. Dawkins also has a light and playful tone which never fails to entertain.
In all, I would heartily recommend the book to anyone who has an interest in the subject, but for whom something like The Selfish Gene might be a little too dry or technical. (Though after this, they'd probably be ready for The Selfish Gene.) And I'd certainly recommend it to anyone who is either on the fence about evolution (or who at least thinks that the criticisms might have some scientific merit), or who needs to marshal their arguments against those criticisms.