Unlike many other furlers, I've never seen Kathy's DVD. I know it's good based on conversations I've had with others who have it. I did however start learning from this book. In my opinion I would go with Kathy's DVD before this book. It will give you a foundation on how they are made, but I wasn't satisfied with any depth on anything else. It's been several years since I even looked at the book, but from what I remember it doesn't give any detail on tapers for anything other than a basic leader.

Tight lines
Brandon