Deer are browsers (not grazers, like cows), which means they eat a bit of everything. There have been lots of funny stories told around here about folks spending big bucks planting expensive food plots, only to see deer eating at the weeds on the edge of the field.
SO...there are preferred foods, and available foods. Here in most of TN, there is almost always SOMETHING to eat, so they generally get to pick their favorites. This does not mean they will eat that food exclusively though. Keeping in the vein of being browsers, they will often leave a great acorn-dropping oak tree and go roam around to find other similar spots, so nothing is set in stone.
This time of the year, most people focus on remaining acorns (which have essentially all dropped, but lots are still on the ground), green fields (ideally with young growth, which tastes the best), and leafy browse (hedgerows, honeysuckle, treetops from recent logging activity, etc.).
Fields that have cold-tolerant plants in them will often stay green throughout most of the winter - winter wheat and clover are two common types, but there are many others. Basically, if there is short green growth coming from the ground, deer are probably eating it, and hoof prints will confirm. If you are hunting a primarily forest habitat, finding a food "source" gets a bit tricky, because sometimes the food is literally scattered here and there all over. In times like this, I will often use satellite images, topographic maps, and visual evidence of trails to decide which way to set up. Sometimes the wind decides for you - your only option is to approach and set up downwind of the bedding areas and their respective trails...hope for the best!
During rifle season, if you can get a clear shooting lane within the woods that's pretty far, you don't have to be terribly good at guessing where to sit and still see deer within range. That's the plus of later season deer hunting - foliage has dropped off, and visibility is always better. On top of that, food availability reduces, so their movements are more predictable. In my humble experience, fields seem to be more popular evening spots, and the woods seem to produce more frequent sightings in the mornings, but your mileage may vary.
About bedding areas - deer are quite willing to bed in different areas from day to day. Magazines report deer habitat like it's the same across the country - in areas where there is thick bedding cover readily available, they may stop in different areas each day. Consequently, they don't have a "bedroom", but more like "a spot on a list of spots that they sometimes bed down". As others mentioned, bucks will cruise through these areas and sniff them out for estrous does to chase/breed. If you get too close to bedding areas and push them out / walk through them and leave scent / etc, they may stay away for a while. They stay in those areas when they feel like they are safe, so it's great to verify that you have found such a spot. If it doesn't produce this season - fear not!- mark it down on a map/GPS, and hunt it next year from a respectful distance. Especially if you have to set up a climbing stand - they can be a bit noisy - you need to stay far enough away to not be heard or smelled while getting situated.
