Muslims have to prepare themselves prior to joining the prayer through a [cleansing ritual] known as wuzu1. The ritual acts of wuzu [are as follows]:
Wash each hand [three times].
Rinse the inner mouth three times.
Wash the nostrils three times by taking in a small amount of water.
Wash the face three times with a handful of water.
First wash the right arm three times and then the left arm up to the elbow.
Wet the hands and gently wipe the head with three fingers from each hand. The forefinger ought to be used to wipe the inner ear and the thumb to clean the outer ear.
Wash both feet up to the ankles three times starting with the right. However, if one puts on a pair of socks in a state of ablution, it is sufficient to pass wet hands over them in all subsequent ablutions thereafter [for one to three days].
[As mentioned above] this collective process is known as wuzu and it must be performed before the namaz can be undertaken.
In situations where water is not available within a radius of at least a mile, or if a person is suffering from some sort of ailment which prohibits the use of water, they may perform tayammum in place of wuzu. The acts of tayammum are as follows:
Pat both hands on a piece of ground or a natural surface.
Pass both hands over ones face.
Wipe both hands over one another.
1 One of the principle objectives of wuzu is to wash those parts of the body that are normally exposed. The namaz has to be offered in a state of physical cleanliness. The rites of wuzu are also a symbolic reminder for Muslims that when outer purity is so important, inner purity must also be kept in mind at all times and they ought to cleanse their hearts of sin before standing in the presence of Allah the Exalted. [Publishers]