With regards to the best place to go for documentation in the manual, the front and back matter features are covered fully in §23.4.1, under subheading Front & Back Matter. Much of that will be of interest to you in setting things up once you get to that point, but in particular, search for the subheading, Linking Front/Back Matter to Compile Groups. By naming your front/back matter folders the same as your book folders, and setting them up in one place, Scrivener is programmed to detect your naming convention and automatically switch between sets based on which book you currently have set as your primary compile group.
I realise a lot of this might be arcane knowledge right at this moment, so I’m speaking more of capabilities than practical details—I mainly just want to assure you that there is a good basis and feature set for handling what you want to do.
Definitely run some searches on the forum as well, for words like “trilogy” and “multiple books”, as you will find lots of practical discussion and advice!