from wikipedia
Gryffindor aka Droygen
Gryffindor values courage, daring, nerve and chivalry. Its mascot is the lion, and its colours are red and gold. The Head of this house is the Transfiguration teacher, Minerva McGonagall, and the house ghost is Nearly Headless Nick. According to Rowling, Gryffindor corresponds roughly to the element of fire. The founder of the house is Godric Gryffindor.
Though Gryffindor is commonly regarded as the 'good' house, not all Gryffindors fall into that category. Cormac McLaggen is the negative qualities of Gryffindor personified; he is ill-tempered and arrogant. Romilda Vane is underhanded and displays a deceptive and devious nature by trying unsuccessfully to ply Harry with a love potion. On the Hogwarts Express, she is somewhat condescending towards Neville Longbottom and Luna Lovegood. However, both McLaggen and Vane certainly are bold, and show confidence, two very Gryffindor qualities, and were therefore sorted into the house. Death Eater Peter Pettigrew also went into this house.
The Gryffindor common room is located in one of the castle's highest towers, the entrance to which is located on the seventh floor in the east wing of the castle and is guarded by a painting of The Fat Lady, who is garbed in a pink dress. She permits entry only after being given the correct password.
Hufflepuff aka Raiden
Hufflepuff, founded by Helga Hufflepuff, values hard work, loyalty, tolerance, and fair play. The house mascot is the badger, and canary yellow and black are its colours. The Head of this house is the Herbology teacher Pomona Sprout, and the house ghost is The Fat Friar. According to Rowling, Hufflepuff corresponds roughly to the element of earth. The Hufflepuff dormitories and common room are located somewhere in the basement, their entrance found through a still-life painting that is somewhere near the kitchens. Students must give a password to the painting to enter. The Hufflepuff common room is filled with yellow hangings and fat armchairs and it has little underground tunnels leading to the dormitories, all of which have perfectly round doors, like barrel tops (very much like a badger sett).
Ravenclaw aka Merrick
Ravenclaw values intelligence, creativity, wit, and wisdom. "Wit beyond measure is man's greatest treasure" is an oft-repeated Ravenclaw proverb. The house mascot is an eagle, the house colours are blue and bronze (changed to blue and silver in the movies). The head of this house is the Charms professor, Filius Flitwick, and the house ghost is The Grey Lady. According to Rowling, Ravenclaw corresponds roughly to the element of air. The founder of this house is Rowena Ravenclaw.
The dormitories are located in Ravenclaw Tower on the west side of the school. The common room, which went undescribed in the series until the climax of Deathly Hallows, is round and filled with blue hangings and fat armchairs, has a domed ceiling painted with stars, and also features a replica statue of Rowena Ravenclaw wearing her diadem. Harry also notes that, by day, the Ravenclaws "would have a spectacular view of the surrounding mountains." A logical riddle must be solved in order to gain entry, whereas the Gryffindor, Hufflepuff and Slytherin common rooms only require a password.
Slytherin aka Vahla'Hanesh
Like Salazar Slytherin, its founder, Slytherin house values ambition, cunning, resourcefulness. The book also suggests that the hunger for power is a characteristic of Slytherins. The animal representing Slytherin is the serpent, and the house colours are green and silver. The Head of this house is Severus Snape in the first five books and most of the sixth book. At the end of the sixth book and in the seventh book, the old Potions master and previous Head of House who has come out of retirement, Horace Slughorn, reassumes authority of the house. The ghost of Slytherin house is The Bloody Baron. According to Rowling, Slytherin corresponds roughly to the element of water. The Slytherin dormitories and common room are reached through a bare stone wall in the dungeons. The Slytherin common room is a long, low, dungeon-style room, located under the Hogwarts Lake, furnished with green lamps and carved armchairs.
For those like myself that know nothing of HP