Tombquest by Michael Northrop

Tombquest book one: Book of the Dead by Michael Northrop is a great read, starting with Alex, a terminally sick boy with constant chest pain almost dying. His mother saves him using the Book of the Dead, a collection of spells made by the Egyptian pharaohs to help guide the souls into the afterlife-and back into their bodies.

With mummies coming to life, New York being overrun by scorpions, and the Death walkers returning, Alex and his friend Ren must try to save the world. Along the way they meet Todtman, a member of a secret organization called the Keepers who make sure that the forces of evil don't rise again.

Northrop manages to add elements of realism to his story, putting references to real old Egyptian legends and myths such as the book of the dead itself, or the Death walkers. Interestingly enough death walkers (or psychopomps in Greek mythology) are mentioned in many different religions throughout the world as guides for souls after they have departed.