Two tie-in non-fiction books have been announced so far for the show.

The Official Season One Companion

Date Due: 18th September 2007
Author: Nicholas Knight
Published by: Titan Books
ISBN-13: 978-1845765354
Pre-order from Amazon.co.uk
Pre-order from Amazon.com

Synopsis (From Amazon.com): Supernatural is the cult CW show from the producers of The O.C. and The X-FiIes, starring Jared Padalecki (Gilmore Girls) and Jensen Ackles (Smallville). Prepare for a spooky roadtrip through the dark heart of America! Brothers Sam and Dean Winchester cruise America’s back roads in their 1967 Chevy Impala, searching for their father. Raised to fight paranormal evil, along the way they confront creatures most people believe exist only in folklore and nightmares, including wendigos, ghosts, pagan gods and demons. This official companion is packed with exclusive interviews, photos, behind the scenes secrets, a complete episode guide, plus a color portrait gallery of the stars.

The "Supernatural" Book of Monsters, Spirits, Demons, and Ghouls

Date Due: September 2007
Author: Alex Irvine
Published by: Harper Paperbacks
ISBN-13: 978-0061367038
Pre-order from Amazon.co.uk
Pre-order from Amazon.com

Synopsis (From the Author's Blog): I'm writing a book tentatively called The Supernatural Guide to the Supernatural, which is a collection of folklore taking the form of the journals of John Winchester, who will be a familiar figure to viewers of the CW (formerly WB) show Supernatural.