On the Kaporet were two golden Cherubs whose wings spread over the Ark. Various commentaries describe the appearance of the Cherubim. The Sages said that their faces were like the faces of a young boy and girl. The Cherubim faced each other and expressed the relationship and the affection shared between the Almighty and the People of Israel. (Sources: Yoma 54, Baba Batra 99) 
At the Sides of the Ark of the Covenant
Contents:   Part I,    Part II,    Part III,    Part IV,    Part V,    Part VI,    Part VII