Garlic coming up in November?
Although it is not ideal to have it coming up now, it won't affect the garlic you harvest next summer very much. I think the extra root growth that the garlic is developing helps compensate for the green leaves that will freeze and die back when the weather turns colder.
There isn't too much you can do about it. Just make sure your garlic doesn't dry out during this time. If you didn't do a big watering right after planting, do it now! When the ground is very dry as it is now, watering a LOT will help to soak it down deep to keep it from drying out in the winter when it is often dry and windy.
Mulching? Be aware that if you mulch, there are many, many cases of long-lasting herbicide residue in mulch, especially straw mulch. We do not mulch anymore at WeeBee Farms since our terrible experience with herbicide residue a few years ago. http://weebeefarms.blogspot.com/2013/10/warning-about-straw-mulch-manure.html
Frost Heave? Something else you may notice in the late winter is some garlic cloves showing on top of the soil, especially if you haven't mulched. This happens because of frost heaves. This, too is not something to worry about as the roots actually pull the garlic back into the ground!