Growing garlic is about as easy as it gets. Put a bulb in the ground in the fall, wait through the winter, and in late spring or summer (depending on the type), you get fresh garlic. There's nothing that compares to it. Not the bottled kind, nor the white papery, decaying bulbs at the grocery store.
The problem is, it's not a cheap habit. If you're ordering, you need to think about it now, and prepare to spend $8.50 or more per half-pound of garlic. And if you want multiple varieties, you better have ground space and serious cash. It adds up quickly!
Or you can start shopping now. Keep an eye out at your farmers markets for garlic. (A word of note: It goes quickly, so arrive early in the day!) Store back a few bulbs for fall, and you'll be ready for planting with a more manageable bunch.
This weekend, I managed to get some early spring heirloom garlic for 50 cents a head. For three dollars, I even with my tendency to cook using lots of garlic, I'll have plenty to plant come October!
If you're thinking about using the types at the grocery store, I'd advise against it. I've had no luck with regular or organic garlic varieties sold in the shops. Good luck!