The four Hogwarts houses are:
GryffindorEditFounder: Godric Gryffindor
Head of House: Minerva McGonagall
Special Magical Object: Gryffindor's Sword
Uses: Only a true Gryffindor may pull this out of the Sorting Hat at the time of utmost need; After Harry's fight with the basilisk, it remains one of the very few weapons that can destroy a Horcrux.
Crest: A gold lion on a red background.
Colours: Gold and Burgundy.
House Ghost: Sir Nicholas de Mimsy-Porpington a.k.a. Nearly Headless Nick.
Motto from the Sorting Hat's 1991 Song: "Their Daring, Nerve and Chivalry set the Gryffindors apart;"
Founder: Rowena RavenclawHead of House: Filius Flitwick
Special Magical Object: Ravenclaw's Diadem
Uses: It keeps the mind clear for thinking, and enhances the wearer's potential intelligence to the maximum possible point.
Crest: A bronze eagle with a royal blue background.
Colours: Bronze and Royal Blue.
House Ghost: Helena Ravenclaw a.k.a. The Grey Lady.
Motto: "Wit Beyond Measure Is Man's Greatest Treasure."
Founder: Helga Hufflepuff
Head of House: Pomona Sprout
Special Magical Object: Hufflepuff's Cup
Uses: Unknown of yet, but is said to contain magical powers.
Crest: A black badger on a yellow background
Colours: Black and Yellow
House Ghost: The Fat Friar
Motto from the Sorting Hat's 1991 Song:"Those patient Hufflepuffs are true,
And unafraid of toil"
Founder: Salazar Slytherin
Head of House: Horace Slughorn
Special Magical Object: Slytherin's Locket
Crest: A silver snake against a green background.
Colours: Silver and Emerald Green.
House Ghost: The Bloody Baron.
Motto from the Sorting Hat's 1991 Song: "Those cunning folks use any means
To achieve their ends."