Roasting

Betty Crocker defines roasting as -
Cook meat uncovered on a rack in a shallow pan in oven without adding liquid.

Wikipedia says-
Roasting is a cooking method that uses dry heat, whether an open flame, oven, or other heat source.  Roasting uses more indirect, diffused heat (as in an oven), and is suitable for slower cooking of meat in a larger, whole piece. Meats and most root and bulb vegetables can be roasted. Any piece of meat, especially red meat, that has been cooked in this fashion is called a roast. In addition, large uncooked cuts of meat are referred to as roasts. A roast joint of meat can take one, two, even three hours to cook - the resulting meat is tender. Also, meats and vegetables prepared in this way are described as "roasted", e.g., roasted chicken or roasted squash.

My even simpler definition:
Put meat in pan, put pan in oven, make hot, eat.
That's all roasting is.
With such a simple definition it's amazing that there seem to be so many ways to make a roast. There really aren't, there are just a lot of ways to make a roast better. Brining, seasoning, stuffing, browing, basting and when and whether or not to cover. Then you go into added vegetables making gravy from the drippings and resting before serving and it's all enough to drive you a bit batty.
I'm going to give you the very basics for roasting beef, chicken and pork. In the future I'll expand with ways to take all of them from a very simple edible meal, to ones that are wonderful.
First off, you can roast everything at 325. Sometimes a slightly different temperature will work better, but 325 will always work. You're working low and slow here.
Second, salt and pepper is all the seasoning that you need. Other flavors can be good, but salt and pepper will always get  you something yummy.
Third, a meat thermometer. You can cook by the time tables given in a cook book, but a $5 meat thermometer will always give you a better answer. It's best not to guess, one undercooked roast should convince you of that. So here we go:
Chicken: I recommend leg quarters, these are the leg and thigh attached with the skin on and the bones still in. They're about the cheapest tastiest meat you can buy. I can feed my whole family of 6 for two nights on $5 in chicken leg quarters.
Preheat oven to 325
Place chicken in a pan
Throw in a couple of tablespoons of butter
Salt and pepper
Place in oven uncovered for about an hour and a half, chicken should be 165 degrees.

Pork: the simplest is a pork loin roast somewhere between 2 and 4 pounds.
Preheat oven to 325
Place pork in pan
Salt and pepper
You can cover or not cover. I like to cover pork for the first hour of cooking either with a lid or tinfoil then uncover for the rest of the time.
Cook until pork reaches 170 degrees.

Beef: basically anything labeled roast in the meat department works. They all have different qualities, the cooking is largely the same.
Preheat oven to 325
Place beef in pan
Salt and pepper
Roast uncovered for 1.5-2 hours, until 160 degrees.

Ok, that's out of the way. Roasting is simple. You can roast chicken pork or beef with less than 5 minutes prep time. Get the kids home, throw the roast in the oven, help them with homework, fold some laundry. Quickly steam up some broccoli, pull the meat out of the oven as your wife walks in the door. You are a domestic god. 
Later I'll throw some recipes out there that will do more than just keep everyone fed. They will be awesome enough to impress your mother in law. Promise.