Are you planting rhizomes or full crows? I recommend buying crowns from Great Lakes Hops. Mine took off in about a week and are now over 7 feet tall and I just planted them this year. Once they are established, they really start to produce, and buying crowns gives them a head start.
Harvest will depend on the variety of hop and where you are. Ideally, you'll just watch your hops for the signs that it is time to harvest.
By the way, you'll want to have a plan for drying them, too.