The book contains line drawings of styles for all the various elements of a window treatment as well as ideas for dealing with different kinds of windows. The book decomposes window treatments into pelmets, valences, etc., etc., etc., with pages of line drawings of styles for each element. Then, it pulls the various elements together into a total look.
I was leant this book, but I found it so helpful I bought my own. It has drawbacks. If you want something simple and/or you plan to make them yourself, this probably isn't the book for you. There are no instructions or measurements of any kind, just the drawings. But if you're working with a decorator who knows a professional, or are a decorator yourself, then this book will help your imagination run wild.