1. Stand erect with heels about as wide apart as your butt-cheeks; angle toes out maybe 30 degrees.
2. After placing bar on back, LEAN FORWARD AT WAIST. How far? Just a few degrees. Leaning isn't bad--it's rounding your back that causes problems. Keep back FLAT--better yet, ARCHED--and help this by looking forward or slightly up.
By the way, you have two options for bar placement: a.) on traps, for more lower quad development ("teardrop around knees"), but more stress on spine; or b.) on rear delts, for more power, emphasis on overall quads, glutes, and spinal erectors (but ironically, less stress on the spine!)--you'll automatically lean more forward this way, and that's okay.
3. Squat down, while poking your butt backwards, as if you're trying to sit down on a baby potty. At the bottom, your knees should be spread apart. …
4. … When you rise with the weight, keep your knees spread apart. If they buckle (I've been there too!) and you can't keep them pointing out, YOU MUST REDUCE THE WEIGHT. The muscles that keep your knees spread apart are the gluteous medius, on the sides of your hips/glutes. They're weaker, and must be strengthened with lighter squats so you can keep your knees apart, and pain-free. …
… Your low back and spinal erectors can be easily overtrained. And your thighs, too. Many people hurt their backs because their thighs are exhausted from too much work and aerobics, so they coast a little bit while asking the erectors to pick up the slack. And when the erectors go, so goes the spinal disc.
… I'm a big believer in "planned undertraining." This generally means each bodypart only once per week.
Personally, I believe anyone can handle either squats OR deadlifts once a week. I don't think both should be attempted, though. Stiff Leg deadlifts? If done properly, they'll probably be okay on a weekly basis. Personally, I squat weekly, and deadlift every other week, with SLDL's weekly also. ON deadlift week, I squat after, and in the same workout, but reduce the regular squat weight by ten pounds.
I think I will swap squat and dead lift every other week, and keep stiff-leg deadlifts on my hamstrings day. I'm with Mr. Carrell on training each body part/section once a week, hence my return to a 4-day routine. I also realize that the deadlift works the biceps perhaps just as much as it works the quads, which is why I'll do it on my quads/biceps day. Clever, right? My basic intuition is that I simply can't neglect the squat, deadlift, and bench press, if I want a "pure" BB routine. I've had a good friend, who suffers no shortage of athletic experience, advise me that perhaps all I should do, in fact, is the deadlift, bench press, and squat thrice weekly (though I think he would approve of including the almighty pullup!).
You wonder why, given my philosophical and theological acumen, I spend so much time on this blog writing about weightlifting. Like I said, it keeps me sane and gives me something good to do whilst real philosophical fruit ripens. I'm currently working through close to a hundred pages of Aquinas every day or two, though this blog does not chart all my inner insights. I take Wittgenstein's position: good philosophical work requires years of patience and suffering (the same thing, etymologically), so, if you, dear reader, want "speedy" "output", go slurp up something from Yahoo or the Huffington Post or Wired.