Anubis was the way ancient Greek historians like Herodotus wrote the Egyptian word Inpu. Inpu, or Anubis, was an Egyptian god, the son of Ra. He was the god of the dead and the underworld in Old Kingdom Egypt. Because jackals went to cemeteries, attracted by the smell of dead people's bodies, Anubis is often shown with the head of a jackal, or entirely in the form of a jackal. His head is black because black was the color of death and of the black dirt in the Nile valley, the symbol of rebirth.
Anubis was important throughout the process of getting a dead person ready to be buried. When the embalmers were making the dead body into a mummy, the head embalmer wore an Anubis costume. Then people also thought of Anubis as the god who weighed your heart to see if you were good or bad after you died.
By the time of the Middle Kingdom, people had stopped thinking of Anubis as the main god of the dead. Instead, they put Osiris in that position. People gradually began to think of Anubis as the son of Osiris, and Osiris' assistant in dealing with the dead.
To find out more about the Egyptian god Anubis, check out these books from Amazon or from your library:
Gods and Goddesses of Ancient Egypt, by Leonard Fisher (1999). For younger kids.
The Egypt Game (Yearling Newbery), by Zilpha Keatley Snyder (reprinted 1985). A great kids' story about kids who pretend to be Egyptian gods and goddesses.
Religion in Ancient Egypt: Gods, Myths, and Personal Practice, by John Baines, David Silverman, and Leonard Lesko (1991). Pretty hard going, but it will tell you everything you need to know about Egyptian religion.