I am a young Muslim and, insha Allah will marry soon. I have some questions which I want to ask so as to refrain from committing something wrong. My questions are:Can the husband touch the wife's private parts to arouse her? Can he kiss her breasts?

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

There is etiquette and conduct for intimate relations between spouses.
1. Perfuming oneself before intercourse. Aisha () said: "I used to perfume the Apostle of Allah and he would pass by his wives and would wake up in the morning wearing his Ihram and exuding scent".
2. What is said before having sex with one's wife: Al Bukhari and Muslim reported: "By the name of Allah, O' Allah, protect us from Satan and keep the Satan away from what you bestow upon us". Abbas reported The Prophet Muhammad (Peace and blessing be upon him) said: "When a person makes sex with his wife and recites this Du'a (supplication). If Allah gives him a baby, Satan will not harm him/her".
3. The legal positions of making sex with one's wife. The sexual intercourse is lawful only in the vagina. But it can be from the front or the back side of the vagina. Al Bukhari and Muslim narrated: "The Jews used to say that when the man has intercourse with his wife from the back of her vagina, he would have a cross-eyed child". Then this verse was revealed: {Your wives are a tilth for you, so go to your tilth (have sexual relations with your wives in any manner as long as it is in the vagina and not in the anus), when or how you will, and send (good deeds, or ask Allâh to bestow upon you pious offspring)}[2:223].
4. It is forbidden to make anal intercourse. Abu Dawood reported from Abu Huraira that the Prophet said: "Whoever has sex with his wife while menstruating or has anal intercourse with her or has come to a soothsayer, he has disbelieved in what has been revealed to Muhammad".
5. It is forbidden to have anal intercourse with one's wife. The Prophet said: "Cursed is any man who has anal intercourse with his wife".
6. It is forbidden to disclose the intimate relations you have with your wife. The Prophet said: "The most wicked among the people in the eye of Allah on the Day of Judgement is the man who goes to his wife and she comes to him and then he divulges her secret".
7. It is obligatory to make Ghusl, ceremonial washing, before prayer anytime he has sex with her even if he does not release any sperm, i.e. any time his sex organ enters her vagina.
8. He can enjoy his wife as he desires provided he avoids what is mentioned above. Allah Says (interpretation of meaning): {They are Lîbas [i.e. body cover, or screen, or Sakan, (i.e. you enjoy the pleasure of living with her - as in Verse 7:189) Tafsir At-Tabarî], for you and you are the same for them.}[2:187].
For more details please refer to fatwa no.: 81608.
Allah knows best.