You either had to know someone who had them or cut a deal with a commercial grower to acquire them. Oh, some garden and nursery supply places might sell you an ornamental vine, but you never knew what variety it would turn out to be or even if it was usable for brewing. Now, however, there are large-scale suppliers who deal in both commercial and retail sales of rhizomes. Wherever you get rhizomes, be sure they are female. Only female hop plants produce cones and if male plants are lurking about, the cones become seeded.
Most brewers prefer seedless hops.
It s never too early to prepare the soil where you plan to plant hops. It helps to give it an entire winter to settle and energize, but a couple weeks before planting will still do the trick. Let age and settle for at least two weeks. Behind the triangle, perhaps three feet away, install a pole with a long strand of strong twine attached to the top, long enough to attach to the stake at the bottom when it becomes necessary in a few weeks. The pole can be anything that does the job.