How many drafts will I go through before the book is ready?
Short answer: I don't know.
For me the first draft is the raw finished book, and then I create a new draft every time I go through and make changes. Sometimes it will be just grammar and spelling, sometimes adding new material, and sometimes re-writing whole sections.
I'm not sure yet how many drafts I'll go through, I want to make sure the book is as good as I can get it, but on the other hand if I wait until it's "perfect" I'll never send it out.
Right now, I'm happy with it, but I want to see what my reviewers say. I may do a little polishing to the draft then send it, or I might make another draft version. For example, I'm toying with the idea of re-writing the whole ending. I'm happy with the way the story ends, but I'm not sure it's written in the best way. I'll post more on this after giving it some thought and getting some feedback.