I am in Maryland, Zone 7. I am planting lettuces, turnips, onions, collards and other greens right now, as well as cabbage, broccoli and brussels sprouts. I'll be planting garlic next month. I planted bush beans and beets about 2 weeks ago. I'll be eating them all before years end except the garlic which I won't harvest till June or July. Collards, Kale, turnips, carrots and several other things can be harvested throughout the winter, even while there is snow on the ground. Hope this helps.

Here is a link that might be useful: Our Community Garden Website

Tennessee:
Start planting! With a little protection in the coldest months, you can keep that garden going through the winter, too.
-O