I've decided to start weightlifting using the Starting Strength program.
The above image shows the barbell position for doing a back squat (the wrists are not in the correct position).
I am unable to to get my arms in that position. With a narrow grip my hands are in front of my shoulders. To get my hands behind my shoulders I need to widen my grip to the point where I'm touching the weights on a 7' bar.
What stretches can I do to increase my flexibility so I can hold the bar correctly?