I grow garlic in containers. It is just like in ground gardening except in a container. Garlic gives very little problems. Just keep it watered when dry, but do not overwater so it's soggy. A good application of compost in the planting mix helps a great deal and organic fertilizer is good also. I use aged horse manure lightly scratched in the suface when the garlic sprouts and a small amout of blood/bone meal. That's about all there is to it. Sit back and let it grow until it's ripe, then harvest.
one other thing to keep in mind......garlic grows much better when the bulbs are given a "dormant" period. Usually a month or two in the fridge before you plant them does the trick.
I've planted garlic before without the "overwintering" period, but the bulbs I got in the end were smaller than they could have been.