For those who are already familiar with the leading (and perhaps not so leading) suspects, and the facts behind the case, this probably isn't for you. For those who are not so well versed, this is a great book.
It starts with an timeline of events (some definitely Ripper related, some less obviously so), and then covers the facts around the murders and the main people definitely associated with the events. After that, the book provides a series of essays from different authors where they express their viewpoint on who was or wasn't the Ripper. This is the meat of the book for most people as many suspects are covered (some twice) and the selections and suspicions are explained and justified. No doubt some will seem ludicrous to you, and some will strike a chord. Overall, I found the quality of the essays somewhat of a mixed bag, but generally interesting.
Finally, there is information about the weather on the day of each murders, as well as a catalogue of TV shows, films, and books about the Ripper.
Do we find out who the real Jack the Ripper is? No, but that isn't really the point of the book (or perhaps even possible now). But it will probably inspire you to further reading!