Garlic growing is something you can do in the winter while you watch skiing on ESPN, or whatever; you plant in the fall and harvest in early summer. What you plant is not seeds; garlic doesn't make any. What some varieties of garlic ("top-setting") do is make a bunch of "bulbils" at the top, which, while they are technically not seeds, can be planted as if they were. They are tiny garlic bulbs, and need two seasons to mature.
Most of the commercial garlic is "bottom setting" meaning that the bulbs just get big and divide, and they send all their energy into that. Top-setting garlic does that too, but the bulbs don't get all the energy so they are not as big.
More information on this can be gotten from Stanley Crawford's book "A Garlic Testament", which is out of print, but not exactly rare. Stan is the major garlic farmer in our area, and he writes well too.