That depends on a couple of different factors, such as length of the book, its complexity and how much time I have to work on it. I will try and release between 1-3 books a year, however you might have to wait up to 2 years between major releases (The Chronicles of New Eden for example).
I do everything for two reasons. Firstly, I enjoy having such a large amount of creative control over my projects, which I would obvioulsy lose if I had to answer to an editor, artist and marketing team. Obviously, if I feel that the quality of a project would benefit from one of the aforementioned services, then I would make use of one. Secondly, those services cost money, and would disturb the zero-cost model that I currently use. If I were to pay for an editor, marketing team and cover designer I would be losing money with every book downloaded, which would then need to be recouped from my regular job. While I am happy to use hundreds of hours of my own time to complete my books, I am not happy to use up funds that are meant to enrich the lives of my family.
Well, I am committed to finishing The Chronicles of New Eden which spans 7 books, as well as The Beggar Chronicles which is a trilogy of books. Beyond that, I have hundreds of story ideas, ranging from standalone works to multi-part epics that run the gamut from sci-fi and fantasy to horror and thriller. After each book is published, I like to sit back and decide what I would like to write next, based on my personal desires.
It varies all the time. Several weeks can go by without me even touching a book, and then, in a single bolt of inspiration, I'll write scores of pages. It really all depends on how I'm feeling on the day.
A lot. Before I've even written the front page I've outlined the characters, the locations, the terms and history of the world and the general chapter storylines. While writing I'll also add to my original outline if any new ideas appear.
Inspiration -> Story Idea -> Outline -> Rough Draft -> First Read Through -> Editing -> Second Read Through -> Editing -> Formatting -> Publication -> Celebration!
Thanks for asking!