I have 2 suggestions:
1. make it possible to create a wiki for each of the novels (articles will be added and edited by logged in users); when you read a few (or even dozens) novels over the course of years and each of them has thousands chapters, you can get lost in it all - from the wiki you can remember long unseen heroes, places, etc..
2. create the possibility of adding "chapters" that will not be marked and counted as chapters - in several novels there are chapters that are not really chapters - e.g. information from the author, announcements, world building informations , specials, and not official chapters written by fans, written for events like Christmas, New year's, etc.).
wiki and unmarked chapters