I've purchased rhizomes from Freshhops, Thyme Garden, and a local brewstore who got them from an unknown source. The local brewstore plants were weak and non-producing on their first year. Product from Freshops and Thyme Garden were strong growers and produced some hops. I am also a part time gardener and typically buy my seed from Thyme Garden as well. Each seed packet has instructions specific to the seed concerning how germinate that seed and get it going.
I'm very happy with my experiences at Freshops and Thyme Garden. I'm plan to buy from Thyme Garden again.
Hope this helps.