I was browsing the Absolute Write FAQ on formatting manuscripts for submission. This FAQ is really interesting, as it goes through all the nitty-gritty questions that many people (including myself) have.
Here’s one of the top tips I found there:
Chapter Start Point
Definition: When beginning a new chapter, the point on the page where the first word of text should begin is often a question.
Use in industry: There is much debate on where on the page to begin typing text upon starting a new book chapter. The two primary methods are: 1) Quad space (two double spaces) from the top margin, after which the words Chapter XX are center justified (and may be bolded, italicized, typed in ALL CAPITALS, or underscored), then drop down two more double spaces and begin to type; or 2) Double space until approximately 1/3 of the way down the page, center justify the words Chapter XX (and may be bolded, italicized, typed in ALL CAPITALS, or underscored, drop down two more double spaces and begin to type. It is recommended that authors seek guidelines from publishers as to how they prefer chapter start points.