The standard golf swing calls for your weight to be equally distributed along your two feet at address. Indeed, regardless of where the ball is located in your stance (forward, back or middle) you should feel as though your feet are supporting your weight equally for most normal golf shots. There are instances where you would want to move away from that position and they are explained within.
In addition to how the weight of your body is distributed across your two feet, it can also vary in where specifically it is placed inside your feet. Indeed, your weight can be distributed level between the back and front of your feet, or it could be located more towards your toes. Finally, it can also be situated towards your heels. All three weight setups are explained.