As a lover of Hellboy and his universe, this was a great find at a used bookstore. Although, as many people have mentioned, this book contains information most of us who have read the comics would know, I like how concise this book is. I was a bit disappointed with a lack of more in-depth details, but I understand Weiner's reasoning for keeping the "mystery" of Hellboy alive, especially for new readers. There is nothing like cracking open one of these comics and letting it come at you with a newness that reading it all in a companion book would ruin.
This is, after all, just your companion guide to Hellboy--it isn't Hellboy himself. But what I did gain was a stream-lined time-line and a succinct summary of the characters of Hellboy that I think would prove useful to anyone, beginner or hard-core fan alike.
What I love the most about this book, however, is the 'inspiration' section. I love reading myths, folktales, and pulp fiction, and while some of the books on the list I have read or know, there are others I look forward to digging into. I appreciate getting a "further reading" section in a companion book about a comic series--it shows how vast the source material for Hellboy is. And it is in those bits and pieces of collected bits and bobs, of information that stuck so well in Mignola's brain, that I truly find fascinating. Plus, now I can read a plethora of books I haven't heard of while simultaneously thinking, "Somewhere in here is a bit of Hellboy," and that is a wonderful thing.