The book is a great tool to know about the process and industry!
But be careful about relying on them as a resource to produce your products. In my case, they sent me the entire order wrong. Colors that were not, sizes that were not and design without my specifications. When I contacted them they only told me that they had invested a lot of money that they could reach an agreement with me to give me merchandise with the correct specifications. They never answered my emails again or sent me the merchandise.