How are squats done correctly? Fitness trainer and model David Rich recommends: "When squatting be sure your knees don't go past your toes. Your butt should sit back and your chest will come slightly forward. For most people doing squats with their legs wide and toes pointed out will make it much easier."
In this video David Rich demonstrates dumbbell squats:
David Rich's fitness site: DavidRichFitness.com