"Homegrown Hops" by David R. Beach
Great book with a lot of Hop growing answers. Hard to find now.
Bought some used editions on ebay last year for backyard growers.
Also: CSU Specialty crops department has some good reading on the website. I wouldn't pay too much attention to the report by Ken and Ogie McGuire of Desert Weyr Farms...not thought over very highly by the other "volunteer hop farmers".