ORIGINAL: Andrew_outdoors
Depends on what you are using. If your bow hunting hitting the shoulder isn't going to do you or the deer much good and you should aim just behind the shoulder. If you have a rifle, taking out the shoulder presents you with an opportunity at the heart, and possibly breaking the shoulder, preventing the animal from getting too far.
Not sure what anatomy book you looked at, but a shoulder shot ain't gonna give you much chance at the heart unless you are at a heller step angle.