Abu Salamah (may Allah be pleased with him) narrated: I used to see a dream which would make me sick till I heard Abu Qatada saying: ‘I too, used to see a dream which would make me sick till I heard the Prophet (peace be upon him) saying: “A good dream is from Allah, so if anyone of you saw a dream which he liked, he should not tell it to anybody except to the one whom he loves, and if he saw a dream which he disliked, then he should seek refuge with Allah from its evil and from the evil of Satan, and spit three times (on his left) and should not tell it to anybody, for it will not harm him.”’(1)
Abu Hurayrah (may Allah be pleased with him) narrated that the Messenger of Allah (peace be upon him) said: "Dreams are of three types: A good vision which is a sort of glad tidings from Allah; a suggestion of one's own mind; and the evil dream (nightmare) that causes pain is from the satan; so if any one of you sees a dream which he does not like he should stand tip and offer Salah."(2)
From the proprieties of good vision are the following:
1- To thank Allah for it.
2- To rejoice and hope for good.
3- To tell it to those whom you love.
From the proprieties of evil dreams are the following:
1- Seeking refuge with Allah against its evil.
2- Slight spatting at one's left shoulder to cast away Satan.
3- Seeking refuge with Allah from the cursed Satan.
4- Changing the side of sleep optimistically to change one's conditions to the better.
5- Offering two Rak`ahs or more to comfort the heart and invoke Allah for protection against its evil.
6- Do not tell it to anyone but if you needed to consult someone, you should consult a scholar or someone can advise him.
(1) Sahih Al Bukhari, No.  and Muslim No. .
(2) Sunan At-Tirmidhi 4/537 and Al Albany graded it as authentic.