Indeed all praise belongs to Allah, and may His peace and blessings be upon His final Messenger Muhammad ibn Abdullah, peace and blessings be upon him, the best in character and manners, to whom we are commanded to follow and emulate. And may Allah's mercy and forgiveness be upon the Prophet's beloved family and noble companions.
To proceed ...
Chapter 1 - Honouring One's Parents
Imam al-Bukhari  opened his book al-Adab al-Mufrad with a chapter concerning the honouring of one's parents, indicating its importance over the other topics he later covers. He began by citing a verse from the Noble Qur'an:
"And We have enjoined on man to be dutiful to his parents." [Al-Qur'an 29:8]
Imam ibn Kathir  said regarding this verse:
"Allah commands His servants to be dutiful to parents ... because a person's parents are the cause of his existence (by His permission). So he must treat them with the utmost kindness and respect, his father for spending on him and his mother because of her compassion for him." [Tafsir ibn Kathir]
In several places in the Qur'an (including what has been cited), Allah mentions obedience to one's parents after commanding His slaves to worship Him alone. So worshipping Allah without committing shirk, which is the greatest sin of all, is connected to honouring one's parents [Tafsir ibn Kathir], therefore this duty is not to be treated lightly. One can find much benefit from the following verses, concerning the manner in which parents should be honoured. Allah says:
"And that you be dutiful to your parents. If one of them or both of them attain old age in your life, say not to them a word of disrespect, nor reprimand them but address them in terms of honour. And lower unto them the wing of submission and humility through mercy, and say: My Lord! Bestow on them Your mercy as they did bring me up when I was young." [Al-Qur'an 17:23-24]
Imam ibn Kathir explains:
"[This] means, do not let them hear anything offensive from you, not even say uff which is the mildest word of disrespect. 'Nor reprimand them' means, do not do anything horrible to them. 'Ata' bin Rabah  said that it meant, 'Do not raise your hand against them.' When Allah forbids speaking and behaving in an obnoxious manner, He commands speaking and behaving in a good manner, so He says ' ... but address them in terms of honour,' meaning gently, kindly, politely, and with respect and appreciation. 'And lower unto them the wing of submission and humility through mercy' means, be humble towards them in your actions. and say 'My Lord! Bestow on them Your Mercy as they did bring me up when I was young' means, say this when they grow old and when they die." [Tafsir ibn Kathir]
Imam al-Bukhari then related the first hadith, indicating its high status over the others to come. 'Abdullah ibn 'Umar  said, "I asked the Prophet, peace and blessings be upon him, which action Allah loves best. He replied, 'Prayer at its proper time.' Then what? I asked. He said, 'Then kindness to parents.' I asked, Then what? He replied, 'Then jihad in the way of Allah.' " He [Ibn 'Umar] added, "He told me about these things. If I had asked him to tell me more, he would have told me more." [Authentic - Irwa (1197), Shaykh al-Albani]
From the benefits of this hadith are:
- We find in the etiquettes of the Companions, that they were keen to please Allah, by performing acts which He loved, as appose to what they loved;
- It contains an example for the one who wishes to know something, that he should ask the people of knowledge; and
- We find that the following three acts are beloved to Allah - The virtue of prayer at its proper time, that is soon after the prayer time has entered as opposed to the prayer of the hypocrites who would leave prayer to just before the commencement of the following one, the kind treatment of parents, and the virtue of jihad in the way of Allah, an act which involves great sacrifice and courage.
And so between the lofty second pillar of Islam, that is prayer at its proper time, and the invitation to martyrdom - that is jihad in the way of Allah, lies the kind treatment of parents, which provides a sufficient exhortation to treat parents better, because by doing so, we earn the pleasure of Allah, following the footsteps of our pious predecessors.
Imam al-Bukhari then relates another narration from Abdullah ibn 'Umar, who said, "The Pleasure of the Lord lies in the pleasure of the parent. The Anger of the Lord lies in the anger of the parent." [Hasan as mawquf, sahih as marfu'. As-Sahihah (515), Shaykh al-Albani]
From the benefits of this narration are: [Shaykh al-Munajjid, refer to Islam-QA: Manners - Honouring One's Parents]
- We learn that Allah's Pleasure is connected to the pleasure of one's parents;
- Likewise, we learn that Allah's Anger is connected to the anger of one's parents;
- Seeking the Pleasure of Allah leads one to Paradise, and provoking His Anger leads one to the Hellfire so this narration is a key to Paradise for the one who wishes to enter it;
- Pleasing one's parents increases the bond the parent and child has, it also makes the home a pleasant environment;
- This narration confirms the Divine attribute of Pleasure, however the Pleasure of Allah is not like the pleasure of His creation, that is because pleasure is an emotion that indicates weakness where-as Allah is free from imperfection, and
- Likewise, this narration confirms the Divine attribute of Anger, however the Anger of Allah is not like the anger of His creation, that is because anger is an emotion which can lead one to do something irrational, which denotes weakness in the creation, where-as the anger of Allah is free from imperfection.
In conclusion, the importance of honouring one's parents are: [Shaykh al-Munajjid, refer to Islam-QA: Manners - Honouring One's Parents]
- Obedience to Allah and His Messenger, peace and blessings be upon him;
- Obeying and honouring one's parents is a means of entering Paradise;
- Respecting and honouring them brings friendship and love;
- Respecting and obeying them is a way of showing gratitude to them because they are the ones who brought you into this world, and
- If a person honours his parents this may be the cause of his own children honouring him.
Furthermore, disobedience to one's parents is from the major sins. However there is no obedience to the creation if it entails disobedience to Allah and His Messenger, peace and blessings be upon him. As for after the parents have died (and if they died in a state of Islam), the child can do many things, such as the following:
- If he has wealth, and his parents were in debt, he can discharge their duty by paying off the debt for them;
- If he has wealth and his parents had not performed hajj, he may perform hajj on their behalf, or pay for someone else to perform hajj on their behalf (if he has fulfilled the obligation), and
- He may pray for forgiveness for them and pray for mercy for them.
This is the end of Chapter 1, may Allah facilitate further explanations in the future.
I close by praising Allah, and may His peace and blessings be upon His Messenger Muhammad. 
(s) Points of Benefit from al-Adab al-Mufrad of Imam al-Bukhari
- He is the Imam of hadith, Abu 'Abdillah Muhammad ibn Isma'il al-Bukhari, born in the year 194H. He is famous for his amazing memory and extensive travels in pursuit of knowledge. He authored several works, the most famous being al-Jami as-Sahih (widely referred to as Sahih al-Bukhari), which is considered the most authentic book after the Book of Allah. He died in 256H, may Allah have mercy upon him.
- He is the famous historian and interpreter of the Qur'an, who authored several books including the monumental al-Bidayah wan-Nihayah (The Beginning and the End). He died in 774H, may Allah have mercy upon him.
- Imam 'Ata' bin Rabah was from the leading tabi'in (successors of the Companions) in tafsir (exegesis of the Qur'an) and student of the noble companion Abdullah ibn Abbas, may Allah be pleased with him. He died 114H.
- He is from the most famous and knowledgeable companions, the son of the Leader of the Believers, 'Umar ibn al-Khattab, may Allah be pleased with him. He died in 73H.
- The translation of al-Adab al-Mufrad can be found at http://bewley.virtualave.net/AdabMufrad.html, its checking by Shaykh al-Albani on http://www.islamworld.net/HADITH/Mufrad.html and an audio explanation of the first few chapters by Salim Morgan at http://www.svis.info/Recordings/select.asp?/Recordings/Salim/SahihAlAdabAlMufrad.