When any of you marries a woman, then let him say

اللّهُـمَّ إِنَّـي أَسْـأَلُـكَ خَيْـرَها، وَخَيْـرَ ما جَبَلْـتَه عَلَـيْه، وَأَعـوذُ بِكَ مِنْ شَـرِّها، وَشَـرِّ ما جَبَلْـتَهَـا عَلَـيْه

”O Allah, I ask You for the goodness of her and the goodness upon which You have created her, and I seek refuge in You from the evil of her and from the evil upon which You have created her”

Allaahumma ‘innee ‘as’aluka khayrahaa wa khayra majabaltahaa ‘alayhi wa ‘a’oothu bika min sharrihaa wa sharri maajabaltahaa ‘alayhi

Reference: Abu Dawud 2/248 and Ibn Majah 1/617. See also Al-Albani, Sahih Ibn Majah 1/324.

Abdullah (bin Mas’ud) (Allah be pleased with him) reported that Allah’s Messenger (Peace be upon him) said to us: O young men, those among you who can support a wife should marry, for it restrains eyes (from casting evil glances) and preserves one from immorality; but he who cannot afford It should observe fast for it is a means of controlling the sexual desire.
Muslim :: Book 8 : Hadith 3233