I'm writing a book. How many spaces should be between the lines? Double space, single space? ?

Question

I am writing a book, and want to know the line space? Should there be 1 or 2 spaces between the lines?

Answer 1

Double space always. If you plan on getting it published, you will need to send it to publishers/agents double spaced every single time.

Answer 2

Double space the drafts so you can make notes in between the lines