Caroline Kepnes books in order
5 books in the catalogue, about 40 hours of reading in all; the shortest takes 7 hours and the longest 8 hours.
1 series and 1 standalone book in the catalogue.
You
5 books
You 8.2 h 
Hidden Bodies 8.2 h 
You Love Me 7.3 h 
For You and Only You 8.2 h You First: A Joe Goldberg Prequel length not known