Here are some quick instruction on how I prepare the Italian Sausage before adding them to the sauce. You will see in the photos that I actually boil the sausage in water right in the frying pan. Fill the pan up with water, just enough to almost cover the sausage. Then cook on high being careful to keep flipping the sausage. Be sure to stab the sausage several times with a fork during cooking. CAREFUL, they squirt! You cook the sausage in this manner until all the water has cooked down and you are left with just the sausage frying in the pan, at this point, you keep cooking to get them nice and browned, even a little black in places, this is ok. Then you throw them in the sauce with the meatballs. This process usually takes about 30 minutes or so. Here are some photos of the Italian Sausage cooking process, may they server you well :-).

If you are going to make the sausage with the sauce, you will want to add the sausagfe to the sauce rigth after you have added the meatballs as noted in the main sauce recipe.