The Cocoknits Sweater Workshop book teaches Julie Weisenberger's method for knitting top-down seamless sweaters. There are patterns included in the book. There is also the "Extended Collection" of Cocoknits Method sweaters, which are sold separately. These separate patterns refer to the method, tips, techniques, etc. which are taught/explained in the book.
Here is some more information about the Cocoknits Method, explaining how it is unique and why it requires a book to accompany the patterns.