This year I ordered mine from Gurney's and Ronniger's where I aslo obtain my seed potatoes, but in year's past I have also used Filaree Farm. (Right now there is a sale at Gurney's)
http://rareseeds.com/2010/03/heirloomgarlic/ (A Good article for garlic Growers form the Seed Bank in Petaluma)
PLANTING TIPS FROM RONNIGER'S: The garlic we offer grows best when fall-planted. Dates vary from mid-September through November, depending on your climate. Usually plant one month before the real cold weather as this will allow time for initial root development and will strengthen the young plant for overwintering.
Water beds a few days before planting if the soil is very dry. This encourages early root growth before winter. Break open your garlic bulbs and loosen them into individual cloves. Select the firmest, largest, best looking cloves for planting. Discard any cloves with signs of decay, irregularities or damage. After deciding on the best spacing pattern for your garlic patch, plant the cloves, root-end down, one inch deep, (that is, to the first knuckle), by simply pressing the clove into the soil.
Later, a light raking over the entire bed will cover the cloves. Where the wind blows, or it can get very cold,
people do plant deeper, 2" - 4" inches is usually the recommended maximum depth.