It is an obligation upon every Mukalaf :
- To Mention the Name of Allah if one remembers 
- And then rinse your mouth and snuff and blow your nose 
- And then wash all of the face 
- And then wash the arms up to an including the elbows.
- And then wipe over the head and include the ears 
- It is acceptable to wipe only a portion of the head 
- (It is acceptable) to wipe over a turban 
- And then one must wash both of his feet and include the ankles
- It is (acceptable) for him to wipe over the Khuff 
- Wudu’ is not a ritually accepted ablution unless it is (performed) intending it (as a preparation) for prayer. 
It is Mustahab preferred to (wash the above mentioned body parts) three times, except for the head.  Also, (it is preferred) to extend the trace of the water. And (it is Mustahab to use) as-Siwaak beforehand. Washing the hands up to the wrists three times before beginning to wash any of the other body parts (is preferred).
The Nullification of Wudu’
Wudu’ is invalidated (becoming null) when anything –constituting a physical (solid or liquid) or a gaseous nature – escapes the privates (penis or vagina, or anus). As well, anything that obligates Ghusl (Ritual bathing) invalidates Wudu’. (In addition) sleeping while lying down , eating camel meat, vomiting, and touching ones’ genitalia (also invalidates Wudu’).
20 Mukalaf is an individual who has met the criteria of being legally obligated to fulfill the acts of worship and be held morally and legally responsible for his deeds, or lack there of. The Mukalaf must be of sound mind, and of mature (puberty) age.
21 Abu Huriara (radiyallahu anhu) narrates that Rasool ul Allah (alayhis salatu was salam) said: “There is no Wudu’ for the one who does not mention Allah’s Name upon it.” (Reported by Ahmed, Abu Dawoud, and Ibn Majah. It has been authenticated by Sh. al-Albani (rahimahullah).
22 Both are Wajib and therefore must be performed. Rasool ul Allah (alayhis salatu was salam) said: “If you are performing Wudu’ then rinse your mouth.” (Reported by Abu Dawoud and it is a Hasan Hadeeth) In Islamic jurisprudence a command is indicative of an obligation as long as there is no evidence to show that it is not an obligation. Rasool ul Allah (alayhis salatu was salam) also said: “If one of you is going to make Wudu’ then you must put water in your nose and then blow it out.” (Reported by Al-Bukhari) A clear proof for the obligation of rinsing the mouth and blowing the nose is found in the Words of Allah (subhanallahu wa ta’ala). He (subhanallahu wa ta’ala) says: “Wash your faces…” Al-Ma’idah 4:6. Logically, it is easy to see that the nose and mouth are integral parts of the face and must be washed as is commanded by Allah and His Messenger (alayhis salatu was salam).
23 The face is from the top of the forehead (roots of the hair) to the lowest point on the chin and from ear to ear.
24 It is Wajib and therefore must be performed. Rasool ul Allah (alayhis salatu was salam) said: “The ears are a part of the head.” (Reported by Ahmed and Abu Dawoud. It has been authenticated by al-Albani (rahimahullah). Rasool ul Allah (alayhis salatu was salam) also said: “When (a person) wipes his head (while performing Wudu”) his sins escape from his head and even from (within) his ears.” Reported by An-Nisa’i and it is authenticated by al-Albani (rahimahullah)
25 ‘Abdullah bin Zaid bin ‘Aasim (radiyallahu anhu) said: “Allah’s Messenger (alayhis salatu was salam) wiped his head from the forehead to the back of his head and then back to the forehead with his (wet) hands.” (Agreed upon).
26 On the authority of al-Mughirah bin Shu’bah (radiyallahu anhu): “The Prophet of Allah (alayhis salatu was salam) performed ablution and passed wet hands on his forelock and over his turban and (he also) wiped over his two Khuff (leather socks).” (Reported by Muslim)
27 Socks, whether leather or not, along with shoes and other foot attire may be wiped over instead of taking them off and washing the feet and the ankles. For the wiping over to be valid the foot attire must be put on while in a state of Wudu’. They also are not to be wiped over for a period that is longer than one day
and one night (5 prayers) for the resident and three days and nights for the traveler. Khuzaymah bin Thabit (radiyallahu anhu) said: “Rasool ul Allah (alayhis salatu was salam) appointed three days and three nights (to be the period) for wiping over the leather socks for the traveler and one day and one night for the resident.” (Reported by Bayhaqee, Ibn Hibbaan, Ibn Abi Shaybah, Abu Dawoud, and At-Tirmithi who said that it was Hasan Saheeh) Wiping over the socks is valid only for ablution and not for ritual bathing. The Wudu’ of an individual remains intact even if the attire is removed or if the time span elapses and he still has not invalidated his Wudu’. The wiping is to be done on the upper surface of the socks by passing wet fingers over them.
28 Rasool ul Allah (alayhis salatu was salam) said: “Surely all matters are judged by their intentions.” (Agreed upon). It is also important to note that the author did not leave out the obligation of Tarteeb (doing in order). This is implied in his stylistic choice of words. He explicitly said And then to signify the sequence that Wudu’ is to be performed in. This sequence is taken directly from the Words of Allah:
( يا أيها الذين آمنوا إذا قمتم إلى الصلاة فاغسلوا وجوهكم و أيديكم إلى المرافق و امسحوا برؤوسكم و أرجلكم إلى الكعبين (سورة المائدة
“O you who believe! When you intend to offer As-Salaah (prayer), wash your faces, and your hands (forearms) up to the elbows and rub (wipe wet hands over your heads and (wash) your feet up to the ankles.” Al-Maidah 5:6
29 There are six compulsory requirements for Wudu’ to be ritually and legally accepted. There must be intention of Wudu’ as a preparation for worship. The intention is not a verbalized statement; it is always an internal process. The face (including nose and mouth) must be washed. The arms must be washed from fingertips to the elbows. The head is to be wiped from front to back with wet hands. The feet and ankles must be washed. All of this must be done in this same order or Tarteeb and at least one time. Complimenting these main requirements there are preferred actions that perfect the Wudu’.
30 Narrated by Abu Hurira (radiyallahu anhu): “I heard Rasool ul Allah (alayhis salatu was salam) saying, “My Ummah will come on the Day of Resurrection with bright faces, hands and feet from the traces of Wudu’.” (Agreed Upon)
31 Rasool ul Allah (alayhis salatu was salam) said: “If I did not fear that it would be excessive upon my Ummah I would have ordered them to (brush their teeth) with every prayer.” (Agreed upon)
32 It is important to point out that there are many other Mustahab deeds that are founded in the Sunnah. It is preferred to begin with the right of the body before the left side. Rasool ul Allah (alayhis salatu was salam) said: “When you perform Wudu’, begin with your right limbs.” Reported by At-Tirmithi, Abu Dawoud, Ibn Majah and it is deemed Saheeh by Ibn Khuzaima. Also, making sure that water penetrates inside the beard. ‘Uthman (radiyallahu anhu) said: “While performing Wudu’, Rasool ul Allah (alayhis salatu was salam) would run his fingers through his beard.” Reported by At-Tirmithi and it was deemed authentic by Ibn Khuzaima. ‘Umar bin al-Khattab (radiyallahu anhu) said that Rasool ul Allah (alayhis salatu was salam) said: “If one after performing ablution completely recites the following Du‘a, ‘Ash-hadu an laa illaha ill-Allahu wahdahu la sharika lahu, wa ash-Hadu anna Muhammadan ‘abduhu wa Rasooluhu: I testify that there is no one worthy of worship by Allah, He is Alone and has no partner and Muhammed is His Slave and Messenger,’ all the eight gates of Jannah (paradise) will be opened for him and he may enter through any gate he wishes.” (Reported by Muslim)
33 Excrement, urine, flatulence, sperm and al-Madhee (seminal fluid or prostatic fluid is a clear substance that comes out of the penis before the ejaculation of sperm due to sexual activity and at times without stimulation) all invalidate Wudu’ immediately upon their emission from man or if applicable to a woman.
34 Things that obligate Ghusl include the emission of a thick liquid from the genitalia, be it in a state of wakefulness or sleep, due to sexual intercourse or not. The meeting of the two sexual organs even if no ejaculation takes place also necessitates Ghusl. The menstruating woman and the woman in her postpartum (post-birth) bleeding are also obligated to perform Ghusl immediately upon the complete stoppage of their respective bleeding. In addition, the person who enters or re-enters into Islam is obligated to perform Ghusl. Further, it is our duties as Muslims to wash our deceased members.
35 Abu Dawoud (radiyallahu anhu) reports with a Saheeh chain of hadeeth that the Sahaaba of Rasool ul Allah (alayhis salatu was salam) used to wait for the night prayer (until they dozed) nodding their heads up and down. Then they would offer the prayer without performing Wudu’. Sound sleep, whether sitting up or lying down both invalidate Wudu’. There should be no differentiation made between the two. Sound sleep is different than nodding off or dozing. If one falls asleep (deep sleep) while sitting down then his Wudu’ is broken. Rasool ul Allah (alayhis salatu was salam) said: “… so he who slept let him make Wudu’.” (Reported by Imam Ahmed and at-Tabraani)
36 On the authority of Jabir bin Samura (radiyallahu anhu) Rasool ul Allah (alayhis salatu was salam) was asked: “Should I make Wudu’ after eating camel’s meat?” He (alayhis salatu was salam) replied: “Yes.” (Reported by Muslim)
37 Rasool ul Allah (alayhis salatu was salam) mentioned: “If one of you touches his penis (genitalia) then he is to make Wudu’.” Reported by At-Tirmithi, Abu Dawoud, an-Nasa’i and Ibn Majah. Yet, we see that Rasool ul Allah (alayhis salatu was salam) was asked as Talq bin ‘Ali (radiyallahu anhu) narrates: “If a man touches his penis during the prayer, should he perform Wudu?” He (alayhis salatu was salam) replied: “No, it is only a part of your body.” Reported by At-Tirmithi, Abu Dawoud, an-Nasa’i and Ibn Majah. Ibn Hibban stated that is Saheeh. The scholars have stated if the genitalia is touched uncovered with lustful intention, then the Wudu’ is nullified, otherwise it is not.