Although rk2001 has done an excellent writeup on Wudu, I felt that certain points needed to be made, and some information had to be added. Wudu is incumbent on every Muslim. Without it one cannot say one's Salat, touch the Holy Qu'ran and do many other basic Islamic acts.
Water which one may use to do Wudu:
Water which was left over after drinking by humans, or halal animals is also clean. One may also use Zamzam water to perform his/her Wudu.
Water which one may not use to do Wudu:
Although this deal with water is largely irrelevant nowadays, it is still important for every Muslim to know, so he/she may know what to do on any given occassion.
Again, rk2001 has done a good job explaining how a proper Wudu is done, but some things need elaboration. There are four farz (compulsory) acts in Wudu, without which, ones Wudu will be incomplete. There are 13 sunnats (highly recommended) acts in Wudu, which, if left out, will result in the Wudu having less rewards and being less beneficial. There are five Mustahab (recommended) in Wudu, which, after doing so, will result in more rewards.
In addition, several things lessen the reward of Wudu and others nullify it altogether. There are four makroohs (cause the full blessings of Wudu to be lost) and eight nawaqise (break the Wudu) in Wudu.
The Farz:
*Masah:
- Wet the hands and fingers.
- Keep the middle finger, ring finger and pinky of each hand together, and keep the thumb and index finger raised and away.
- Keeping the thumb and index finger away from the head, pass the three fingers from the forehead to the upper portion of the nape.
- Place the palm of both hands on each side of the head, bringing them towards the forehead.
- Clean out the opening of your ear with the index finger, and the back of your ear with your thumb.
- Then make masah of your nape with the back of your middle finger, ring finger and the pinky.
- Finally, pass the fingers of both hands through eachother.
- There is also a masah for the feet which is done while washing the feet. Using the left pinky, clean between the fingers of your feet starting with the most right finger (the small finger on the right foot) and ending with the most left finger (the small finger on the left foot).
The Sunnats:
The Mustahabs:
The Makroohs:
The Nawaqise: