Cohen's book contains facts about Star Trek, but there's nothing strange or amazing therein. The facts are mostly in the form of very brief summaries of a few episodes or (similarly very brief) biographies of a few principal actors. Almost everything in the book will be known to anyone who bothered to watch the show ("When the series begins Kirk is in his mid-thirties, and holds the rank of captain with a starship command."), and the little that might not be is generally of little interest ("Another of Bill Shatner's current enthusiasms is the horses that he rides and breeds on his southern California ranch.").
The most interesting part of this book is the chapter on the fans, which talks about the letter-writing campaign to save Star Trek from cancellation, fanzines, conventions, and the broader impact of Star Trek in the years since its cancellation.
The book concludes with a 22-question trivia quiz.
Stephen E. Whitfield's The Making of Star Trek is by far this book's superior, and even Wikipedia is more informative.