Cleanliness (Taharah) is an important precondition of Islamic worship. Wudu is an essential part of Cleanliness. Salah(prayer) is not valid without Wudu' or Tayammum(dry Ablution). Allah says in the Qur'an ;
Step-by-step guide with pictures:
1. First make Niyyah (Intention) that you are making Wudu' for Salah and begin saying. "Bismillah.." (In the name of Allah, the most merciful and the most kind). Wash both hands up to the wrist three times, making sure that water has reached between the fingers.
2. Put a handful of water into your mouth and rinse it thoroughly three times
3, Sniff water into your nostrils three times to clean them.
4.Then wash the tip of the nose. Do this action three times.
5. Wash your face three times from right ear to left ear and from forehead to throat.
6. Wash your face three times from right ear to left ear and from forehead to throat.
7. Wash your right arm and then your left arm thoroughly from wrist up to elbow three times.
8 a) Move the wet palms over the head,
8 b) and then from the top of forehead to the back of the head.
9) Pass the wet tips of index fingers into the grooves and holes of both ears and also pass the wet thumbs behind the ears
10. Finally, wash both feet to the ankles starting from the right, making sure that water has reached between the toes and all other parts of the feet.
"Ash-hadu an la ilaha illal lahu wa ash-hadu anna Muammadan 'abduhu wa rasuluh."
Meaning: I testify that there is no god but Allah and He is One and has no partner and I also testify that Muhammad is His servant and messenger.