First year you won't get too many useable hops. The goal is to get the bines to grow as much as possible, which maximizes the root ball. I wouldn't prune at all. Year 2+, a small number of bines per plant will maximize height and hop growth.
Give a man a beer, waste an hour. Teach a man to brew, and waste a lifetime! Bill Owen quote
Join the Beacon Point (Aurora, CO) Brewclub on Facebook- casual, fun brewing, drinking, socializing!