Proofs from Qur'an:
So (it will be), and We shall marry them to Houris (female fair ones)
with wide, lovely eyes. (Ad-Dukhan 44:54)
They will recline (with ease) on thrones arranged in ranks. And We
shall marry them to Houris (female, fair ones) with wide lovely eyes.
(At-Tur 52:20)
Houris (beautiful, fair females) restrained in pavilions; (Ar-Rahman
55:72)
And (there will be) Houris (fair females) with wide, lovely eyes (as
wives for the pious), (Al-Waqi'ah 56:22)
http://thenoblequran.com/sps/nbq/
Proofs from Hadith:
Narrated Abu Huraira: The Prophet said, "The first batch (of people)
who will enter Paradise will be (glittering) like the full moon, and
the batch next to them will be (glittering) like the most brilliant
star in the sky. Their hearts will be as if the heart of a single man,
for they will have neither enmity nor jealousy amongst themselves;
everyone will have two wives from the houris, (who will be so
beautiful, pure and transparent that) the marrow of the bones of their
legs will be seen through the bones and the flesh." [Al-Bukhari vol.4,
book 54, number 476]
Narrated Anas (R.A.): The Prophet (صلی اللہ علیہ وسلم) said, "A single
endeavor (of fighting) in Allah's Cause in the afternoon or in the
forenoon is better than all the world and whatever is in it. A place
in Paradise as small as the bow or lash of one of you is better than
all the world and whatever is in it. And if a houri from Paradise
appeared to the people of the earth, she would fill the space between
Heaven and the Earth with light and pleasant scent and her head cover
is better than the world and whatever is in it." [Al-Bukhari volume 4,
book 52, number 53]
Righteous women will become the leader amongst the several houris which will be married to each righteous man.