Like all the "For Dummies" books, this is a good purchase if you really don't know anything about the subject. I think there's a place for these books. They're a good for absolute beginners who want to get started. They can also help you decide if you like something enough to find out more about it. It's just that they're not that cheap and I think they almost always leave you wanting more.
If you know anything about hockey, you'll probably find much of this book useless or uninteresting. There are better books on how to play hockey (like Percival's Hockey Handbook) and about the sport (like Total Hockey) out there that are worth buying. You'll probably skim this book quickly and never pick it up again.
If you're just learning, this will give you all the basics along with a few bits of interesting information. Still, I'll bet you don't read this thing more than once. There are better books to get into the various aspects of hockey as a player, parent of a player, or fan.
I'd recommend this book to someone who just wants to watch hockey and have some idea what's going on...although finding a friend who can tell you is probably better and will only cost you a beer or two. If this book were cheaper or went a bit further I'd recommend it to more people. As it is, all I can say is with the title right on the front of the book you can't say they lied to you!
PS: This review isn't meant as a slam to the authors who I think did a good job. It's just a problem with this series or format. It serves a purpose, just a very narrow one.
