Garlic is one of those easy crops to grow and the seed catalogs have many varieties to choose. I stick with my favorites, a German Porcelain and an elephant garlic. I plant leftover stock from lasts year's crop as garlic is one of those crops that will replenish itself. If you didn't save some of your last crop you can order online from any of many sources. Another option is to buy a few garlic bulbs at the grocery to plant. Be advised, grocery garlic has been treated with a sprout inhibiter so it won't sprout in the store but if you plant these bulbs they will eventually sprout and grow.
Planting is easy, separate the bulbs into individual cloves and plant the garlic cloves 4-6" apart. The depth of planting should be twice the height of the cloves...most cloves are 1" tall, plant them 2" deep.