According to the showrunner Craig DiGregorio, the Books from Beyond was based on the interior of a store they saw in Los Angeles
The Eligos demon costume took several months to be designed, and the actor wearing it was almost walking naked on the set.
This is the first time a demon is directly summoned from the book on-screen.
The series is set in the USA where people drive on the right, but filmed in New Zealand where people drive on the left. Does this explain why Ruby/Lucy Lawless is always shown driving right up the middle of the road?