The Wheel of Time show is based on the novel series by Robert Jordan and contains fourteen books in the main series. The series is comprised of "The Eye of the World", "The Great Hunt", "The Dragon Reborn", "The Shadow Rising", "The Fires of Heaven", "Lord of Chaos", "A Crown of Swords", "The Path of Daggers", "Winter's Heart", "Crossroads of Twilight", "Knife of Dreams", "The Gathering Storm", "Towers of Midnight", and "A Memory of Light".
The Wheel of Time also has a number of companion books which provide additional information about the world and characters in the series. These include "New Spring: The Novel", The World of Robert Jordan's The Wheel of Time", "The Wheel of Time Companion" and "The Wheel of Time: Sourcebook and Roleplaying Game Guide".
In total, The Wheel of Time show is based on 18 books. It is an expansive series and provides plenty of material for the show to draw from. For those looking for more information about The Wheel of Time, you can find out more here: http://www.tor.com/series/wheel-of-time/
