How to Discipline Children in Islam
Question

I find disciplining my children difficult and often I become angry and beat them. Can you give me any advice on the subject, as well as any books that would be appropriate to read?
Praise be to Allah.Disciplining children is the duty of parents
Raising and educating children is one of the duties required of parents. Allah has enjoined that in the Quran, and the Messenger (peace and blessings of Allah be upon him) also enjoined that. Allah says (interpretation of the meaning): 
“O you who believe! Ward off yourselves and your families against a Fire (Hell) whose fuel is men and stones, over which are (appointed) angels stern (and) severe, who disobey not, (from executing) the Commands they receive from Allah, but do that which they are commanded” [Al-Tahrim 66:6]
Imam al-Tabari said, commenting on this verse: 
“Here Allah is saying: O you who believe in Allah and His Messenger, “Ward off yourselves” teach one another that which will protect those who do it from the Fire and ward it off from them, if it is done in obedience to Allah and they do it in obedience to Allah. The phrase “and your families against a Fire” means, and teach your families to do acts of obedience to Allah so that they may protect themselves from the Fire." (Tafsir al-Tabari, 18/165 )
Al-Qurtubi said: 
“Muqatil said: This is a duty that he owes to himself, his children, his family and his male and female slaves. Ilkiya said: We have to teach our children and families religious commitment and goodness, and what they cannot do without of etiquette. This is what Allah says (interpretation of the meaning): 
“And enjoin As-Salah (the prayer) on your family, and be patient in offering them [i.e. the Sala (prayers)].” [Ta-Ha 20:132]
And Allah said to the Prophet (peace and blessings of Allah be upon him) (interpretation of the meaning): 
“And warn your tribe (O Muhammad) of near kindred.” [Al-Shu’ara 26:214]
And the Prophet (peace and blessings of Allah be upon him) said: 
“And teach them (children) to pray when they are seven years old.”(Tafsir al-Qurtubi, 18/196 )
The Muslim – any Muslim – is a da’iyah (propagator) who calls people to Allah, so the first people whom he calls should be his children and family who are close to him. When Allah commanded His Messenger (peace and blessings of Allah be upon him) to call people, He said (interpretation of the meaning): 
“And warn your tribe (O Muhammad) of near kindred.” [Al-Shu’ara 26:214] because they are the first people to whom he should do good and show mercy.  
The Messenger (peace and blessings of Allah be upon him) gave the parents the responsibility of raising the children and made that obligatory upon them. 
It was narrated that ‘Abd-Allah ibn ‘Umar said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: “Each of you is a shepherd and each of you is responsible for his flock. The ruler is a shepherd and is responsible for his flock. A man is the shepherd of his family and is responsible for his flock. A woman is the shepherd of her husband’s household and is responsible for her flock. A servant is the shepherd of his master’s wealth and is responsible for his flock.” He said: and I think he said, “A man is the shepherd of his father’s wealth and is responsible for his flock. Each of you is a shepherd and is responsible for his flock.”  (Narrated by al-Bukhari, 583; Muslim, 1829) 
How to discipline children

Part of your duty is to bring them up from a young age to love Allah and His Messenger and to love the teachings of Islam. You should tell them that Allah has a Paradise and a Hell; that His Hell is hot and its fuel is men and stones. The following story contains an important lesson. 

Ibn al-Jawzi said: 
“There was a king who had a lot of wealth, and he had a daughter and no other children. He loved her very much, and he used to let her enjoy all kinds of entertainment. This went on for a long time. Beside the king there lived a devoted worshipper, and whilst he was reciting one night, he raised his voice saying, “O you who believe! Ward off yourselves and your families against a Fire (Hell) whose fuel is men and stones” [Al-Tahrim 66:6 – interpretation of the meaning]. 
The girl heard his recitation and said to her servants, “Stop!” But they did not stop. The worshipper started to repeat the verse, and the girl kept telling them to stop, but they did not stop. She put her hands to her collar and tore her garment, and they went to her father and told him the story. He went to her and said, “My dear, what happened to you tonight? What made you weep?” and he hugged her. She said, “I ask you by Allah, O my father, to tell me, does Allah have a Fire the fuel of which is men and stones?” He said, “Yes.” She asked him, “Why did you not tell me? By Allah I will not eat any good food or sleep on any soft bed until I know whether my abode is in Paradise or Hell.” (Safwat al-Safwah, 4/437-438 )

You have to keep them away from the places of immorality and misguidance; do not leave them to grow up with evil things from the television etc, then after that expect them to be righteous, for whoever sows thorns cannot harvest grapes.  That should be done when they are young, so that it will be easy for them when they grow up, and they will get used to it, and it will be easy for you to tell them what to do and what not to do, and it will be easy for them to obey you. 

It was narrated that Abu Hurayrah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings of Allah be upon him) said: “Teach your children to pray when they are seven years old, and smack them (lightly) if they do not do so when they are ten, and separate them in their beds.” (Narrated by Abu Dawud, 495; classed as sahih (authentic) by Shaykh al-Albani in Sahih al-Jami’, 5868)

But the educator must be merciful, forbearing, easy-going and approachable, not foul-mouthed or unkempt, arguing in a manner that is better, far removed from insulting, rebuking and beating, unless the child is one of those who willfully disobey and rejects his father’s commands and neglects his duties and does haram (impermissible) things; in that case it is better to use stern measures with him, without causing him harm. 

Al-Minawi said: 
“For a father to discipline his child when he reaches the age of discernment means that he should raise him with the characteristics of the righteous believers and protect him from mixing with evildoers; he should teach him the Quran and good manners and the language of the Arabs, let him hear the Sunnah (Prophetic traditions) and the sayings of the Salaf (pious predecessors) and teach him the religious rulings that he cannot do without. He should warn him then smack him (lightly) if he does not pray etc. That will be better for him than giving a sa’ (dry measure of food) in charity, because if he teaches him properly, his actions will be among his ongoing charity, whereas the reward for a sa’ of charity is limited, but that will last as long as the child lives. Discipline is the nourishment of the soul, and training it for the Hereafter.  
“O you who believe! Ward off yourselves and your families against a Fire (Hell)…” [Al-Tahrim 66:6 – interpretation of the meaning]
Protecting yourself and your family from it means reminding them of Hell. Discipline includes preaching, warning, threatening, smacking (lightly, if necessary), detaining, giving and being kind. Disciplining one who is good and noble is different from disciplining one who is difficult and ignoble." (Fayd al-Qadir, 5/257) 

Smacking (lightly) is a means of correcting the child; it is not something that is wanted in and of itself, rather it is resorted to if the child is stubborn and disobedient. 

There is a system of punishment in Islam, and there are many punishments in Islam, such as the hadd punishments for adultery, theft, slander, etc. All of these are prescribed in order to set the people straight and put a stop to their evil. 
Concerning such matters the Prophet (peace and blessings of Allah be upon him) advised parents to deter their children from doing wrong. 
It was narrated from Ibn 'Abbas that the Messenger of Allah (peace and blessings of Allah be upon him) said: “Hang your whip where the members of the household can see it, for that will discipline them.”  (Narrated by al-Tabarani, 10/248; its isnad was classed as hasan by al-Haythami in Majma’ al-Zawaid, 8/106)
Al-Albani said in Sahih al-Jami’, 4022, it is hasan (good). 

So raising children should be a balance between encouragement and warning. The most important element of all is making the environment in which the children live a good one, by providing the means whereby they may be guided; this means that their educators should be religiously committed, including their parents. 
One of the ways in which a parent may be successful in raising his children is to use a cassette player to play tapes of teachings, Quran recitation, khutbahs (sermons)and lessons of scholars, for there are many available.  

References on raising children in Islam 
With regard to the books that you asked about, which you can refer to with regard to raising children, we recommend the following: 

Tarbiyat al-Atfal fi Rihab al-Islam by Muhammad Hamid al-Nasir and Khawlah ‘Abd al-Qadir Darwish 
Kayfa yurabbi al-Muslim waladahu by Muhammad Sa’id al-Mawlawi 
Tarbiyat al-Abna fi’l-Islam by Muhammad Jamil Zayno 
Kayfa nurabbi Atfalana by Mahmoud Mahdi al-Istanbuli 
Mas-uliyyat al-Abb al-Muslim fi Tarbiyat al-Walad by ‘Adnan Ba Harith 

And Allah knows best.