Grinding noise

When I drive my 72 skylark its fine no problems.. but when it comes time to stop there is a sort of grinding noise when i press the breaks..it doesnt happen all the time but it happens and it shakes the entire front end of the car, does it sound like i need new brake shoes?? or does it sound like there is a bigger problem..also on a side note does anybody know what tools i need and how to tighten the doors? the shop tht painted my car put the doors on wrong and his shop is closed now so i need to figure out how to fix the problem on my own so tht when i shut my doors they do not rub against the front quarter panels