For the most part, a readable presentation of werewolf history, if somewhat dated. As many writings do, spends a lot of time on non-werewolf topics then weakly connects them to lycanthropy, something that seems to happen due to how limited the werewolf corpus actually is.
I cannot recommend this, however, due to its suspect informational quality - there's very few citations, and the author doesn't have a relevant background (he's a book seller, not even a writer; let alone an academic or anything dealing with folklore/history), and this shows in the many factual errors scattered throughout, seeping out further into questionable uncritical analyses. The simplest examples I can give are believing urban myths around periods synching with the moon or with other women in closer proximity, or the belief that ergot "to all intents and purposes" doses you with LSD. The general presentation of werewolf history isn't that levels of incorrect, but the constant small errors leave the whole project weak; read with care.
There are a few worthwhile inclusions that aren't given focus in other works I've read. One is the connection between the myths of Lycaon and Tantalus (page 47), another is the inclusion of a few post-witch trials accusations of people being werewolves (page 185-6).
In general, it'd be preferable to read a better work, and then supplement it with this by flicking through for any new pieces of information rather than relying on this as your soul source.