SID sheep production handbook. It was/is? produced by the american sheep industry association, and is very widespread. It is a wonderful technical book, not real great for additional subjects, like spinning, etc... But it has most of the major breeds & compares them, lists all sheep diseases with signs & treatment (conventional), has a section on predators, shearing, breeding, etc etc... A huge book. Not real focused on the "natural" way of raising sheep, but a wonderful book nonetheless.