Is it meant to be an informative sort of book? Like Islamic History: A Very Short Introduction by Adam J. Silverstein which might be good, to see how you rate it as an introduction.
Or are we talking a novel that refers to islam and how accurate the references are. In which case you could try the Islam Quintet, by Tariq Ali Which, unsurprisingly, is 5 books which deal with the destruction of moorish culture and the rebellions against all that. I read one ages ago, and it was pretty good, but I can't recall how accurate or even relevant it was.