I only use the foam roller padding if I'm trying to increase my max squat and/or my shoulders are killin'.
Like any exercise, it IS all about form. When you put the weight over your shoulders, try to push it up a tiiiiiiny bit with your hands. You will not *actually* be pushing it up in any way, just simulating the motion. It does wonders for taking the weight off your shoulders.
Before squatting, make sure that the bar is placed EXACTLY in the center of your back (being a little off center can really hinder your progress) and positioned in a comfortable spot between your delts and shoulder blades. Trust me; there IS a comfortable spot. Sometimes, it takes awhile to find it, but it's there.
And of course, the more you challenge yourself (and the more you do it), the easier it gets. You will eventually build your "shelf" too - and I do know all this from personal experience - back in March, I could barely squat the bar. I HATED the way the weight felt on my shoulders and I pulled a muscle in my thigh from going ALLLLLLL the way down (which is unnecessary - going down to the ground is potentially dangerous depending how much weight you are using - despite the fact that some meatheads insist it is the only way). Now? My max is 315
theloula - I am not Mel, but I can answer your question. Push the weight back and push your body forward /duck/run as much as you possibly can.