If you are submitting your document to a publisher, then this template/format is recommended.
It generates traditional manuscript-style pages for books or scholarly journal articles. The blank file and template both include design and typographic settings to accommodate common text elements: headings, subtitles, extracts, etc. The font is Courier New, 12-point, set on a 24-point line. All type is the same size. The design is “left aligned”— all titles, subtitles, headings, etc. are lined up on the left margin. Text paragraphs, titles, headings, references, and endnotes are not justified. A single blank line (12 points) is added between paragraphs.
Available at: http://works.bepress.com/paul_royster/10/