One of the places I have seen the heel toe thing.

"How to do it: The Allen bolt that holds the seat post in place is on the side of the frame by the base of the seat post. Pedal backward until one pedal is completely at the bottom. Your heel should just be able to touch the lower pedal with your leg straight so when you place the ball of the foot on the pedal (ball over the center of the pedal) your knee will bend. This is a great starting place for seat height"
http://www.caree.org/bike101bikefit.htm