I love being able to plant in the fall. Things usually get pretty hectic in the spring garden, so anything that can be planted in the fall is a very good thing... a VERY good thing!
You can plant garlic in the spring too, but planting garlic in the fall will yield bigger and better garlic bulbs. So, you should definitely plant garlic in the fall if at all possible! I mean, who doesn't want the biggest and best garlic possible?
Here in south-eastern Virginia, we usually plant garlic in mid-late November. You pretty much just want to plant it a few weeks after your first frost and before the ground freezes for winter. So, depending on where you live, the date range for planting could be anywhere from October thru January.
Garlic is super easy to plant. Just pull the individual garlic cloves off of each garlic bulb (full bulbs shown above) and plant each clove with it's pointy end up about 2 inches deep and 5 or 6 inches apart. You should mulch them a bit too for their winter siesta and then in the spring as they start to pop through the ground, pull the mulch back and they'll take off.
You'll have a garlic bounty in mid summer ... and that's also a VERY good thing!