This book is definitely comprehensive, but that is also perhaps a negative trait. It is something that is good to use as a reference, or if you want information in a specific basic area. However, reading it can be rather tedious, as his style is very dry and boring. It does provide a good solid foundation in Islam, but only for someone who can stand it! If you have never read anthing on Islam and truly want to learn, but something by John Esposito, his writing is a little more accessible.