When you are cooking sausage in a skillet, you want to make sure that the skillet you are using is either non-stick or a cast iron skillet. You will want to warm the skillet over medium heat to start, and cook 2-3 minutes on each side or until cooked all the way through. Since sausages contain fat, it is not necessary to add oil or butter to the pan, since the sausages will start to create grease when cooking.