Manny- here is the deal in VA. We can not bait anything, we can hunt at night and it works very well with a light. Depending on where you hunt we have some fox or some more fox, but the coyotes have seen to it that we don't have alot of fox. Coyotes are not evenly distributed throught out VA either, but overall we do have alot of them. Hunting fox and coyotes requires two different tactics, at least it has for me. Fox will cover open ground most of the time and seem to be at ease doing it. Therefore you can watch them come in and take your time with the shot. Coyotes will not come into the open unless it is absolutely nessesary, they are good at circleing the call weather it is up wind, down wind or sideways. You might get a pup to come in hard, but after they get any age on them, they will not show themselve until they are right on top of you. Coyotes are like crows, when they know you can't shoot them, they are easy to find, but when you have a gun, you rarely see one.
Because shooting distances are usually not long here in VA, a 22 Hornet would be just fine, but a 221 FB would have a little more oomph. I use a 223 and a 17FB and both put them down for the count. If I am hunting heavy woods, then I will carry a 12ga with #4 buck.
I have hunted out of tree stands in the past on occasion, but they have not produced for me because the coyote usually comes in behind me and catches me. Don't ever think that they don't know where every treestand in thier territory is, they do. It is best to hunt from the ground and easier to pinpoint where the footsteps come from. He will be hard enough to spot as it is, you will probably hear him before you see him, at least I do.
Calls: there is no hard fast rule, but as sure as I am writing this, if the only call you are using is a rabbit in distress, that is the one that doesn't work! I use rabbit, jack rabbit, kittens, fawns, ducks, and stuff I makeup. You just need to find the key for that day. I start off soft and get louder, it makes more sense to me. On my very first stand ever, I settled in, had my rifle in my lap, put the call to my lips and let loose, at the first sound a coyote came out of the woods 50yds away at full stride, he was literally in my lap before I could move, He veered to my right at the last moment. I don't know who it scared more, but I do know it seemed like about 5 minutes before my heart started beating again, needless to say I WAS HOOKED!!!
You are just going to have to find what works for you.
Good luck