http://thestir.cafemom.com/baby/108322/9_lifesaving_car_seat_rules

I would love it if every mom I came across could read this. I drive around and see so many children, who;s parents clearly love them so much, not buckled into their seats properly. some highlights from the blog...

Rule #1: Make Sure Shoulder Straps Are in Proper Position

Rule #2: Rear-Facing Is the Responsible Choice Unless your child has serious medical problems, they have to rear-face until they literally cannot anymore. With all the new, cheaper seats with 40-pound or higher rear-facing limits, it's possible for anyone to have a seat that will keep their child rear-facing until the bare minimum of 2 years old and 30 pounds, as per the AAP's improved guidelines. But as they state, 2 years is the bare minimum -- your child is still significantly safer rear-facing until you cannot fit them that way any longer. After all, it's 500 percent safer.
(I include this whole rule because parent's seem to have trouble with it)

Rule #3: No Gaps Allowed Between Baby's Crotch/Groin Area and Harness

Rule #4: Be Sure the Chest Clip Is Positioned Properly on the Chest

Rule #5: Know the Proper Guidelines for Outgrowing a Seat

Rule #6: Straps Need to Pass "The Pinch Test"
(updated from the 2 fingers under the strap)

Rule #7: Coats Are Not Allowed

please jump over there and read the whole thing. :)