David Kerrhas been running Devon Pond Plants for over twenty years, growing and retailing aquatic plants. Prior to this, he studied Zoology followed by a master’s in Fish Biology, before building and managing a trout and ornamental fish farm, further specialising in Japanese koi and pond construction. As such, he has a wide range of practical experience of pond keeping issues and a deep understanding of the factors involved in creating successful ponds.
There certainly are plenty of mistakes the would-be pond digger can make, and Kerr has made them all, so you don't have to. In short, Kerr's book really is an extremely practical guide, follow his advise and you won't go far wrong.