It's easy to look down our nose at this book today and say it's not great but to do so is to totally ignore the perspective of WHEN it was written. In the early 70s, Jaws was totally original, totally fresh. The point of view from the shark had never been done before and to see it was exhilirating.
I agree with others who pooh-pooh this book for the cheap, soap opera-ish romance between Cooper and Brody's wife; even back then, this wasn't particularly well done, nor did it serve to advance the plot. That's why it was completely removed from the film version, so the movie could focus completely on how do we deal with the menacing shark.
Still, Jaws was and always be one of the great thrillers of all time - both as a book and a movie. Peter Benchely was a master who, ironically, ended up dedicating his life to shark preservation after villifying them with this book. How sad to learn of his passing earlier this year. But everyone should read Jaws! Book lovers and movie lovers alike; it gives us all a great sense of where the truly great stories come from.