Just like the T.V show the books follow the haunting adventures of two brothers whose mother was murdered when they were very young by an unknown entity. Their father raised the brothers to be hunters of all the things that go bump in the night. It has everything you could ever ask for and takes the readers and watchers on a roller coaster ride of emotions.
The books take place in-between episodes so I would also suggest you binge watch all TEN seasons on Netflix (or at least season 1 and 2 before you read the books because they will contain spoilers.)
Note: I would ONLY recommend readers to purchase these four books from HARPER COLLINS (other fan fiction exists on Amazon and are not as good)
Read in this order.