What form of Namaskaram to Gods does Hinduism prescribe?

“In Hinduism, the prescribed form of Namaskaram to god is the Sashtanga Namaskaram. The “Sashatanga” is where one lies down flat on the stomach with eight limbs touching the ground. The eight limbs are chest, head, hands, feet, knees, body, mind, and speech. This namaskaram is generally done by men.Traditionally, women do only “panchanga” namaskaram and not the other two.A “panchanga” namaskaram is where one, generally, a woman kneels down with palms joined together or touching the feet of the revered one in front. A woman does not do sashtanga namaskaram for the following reason. Our rule makers (makers of sastras) while making the rule that namaskara should be by lowering the body prostrate on the ground, eschewing every thought of self importance and finding the lowest level with the ground, they duly thought of the Universal Mother aspect (matrutwam) of Parasakthi (Ambal) which is a distinguishing divine principle in women, and took care not to imply any suggestion of lowering its importance. They ruled that the part of the body which sustains the growth of the foetus during pregnancy and the part that creates within itself the nourishment for the new born and feeds it should not be allowed to come in contact with the ground. If the torso should not touch the ground, then the shoulders have to be excluded so that the namaskara can conveniently performed. Thus, excluding the three angas, in their case it becomes panchanga. This also symbolises the need for women to have a “bending” nature. Bowing down itself means bending and it seems that the namaskara performed by women is real bow down.”

Ref: http://bharathkidilse.blogspot.in/2009/10/namaste.html