Writing is an exercise. You should devote 20 or 30 minutes a day to it. Outline your chapters. If you can state what your novel will be about in one paragraph, you can write a book. Writing is inspiration enclosed in structure. It is ideas fleshed out. But always remember; it is an exercise.
Does anyone know how long this thread should have been?
One question; One answer.
Write, write, write! Write drunk or sober. Your best critic is you the morning after!
A series of novels would have a similar pattern of chapter and page length but differing authors, but I guess the length of any individual novel would be down to content.