As little as possible. If you can just get your text in there, hyperlink what you want hyperlinked, bold and italicize what all you want, I will do the rest. I will assign heading styles, drop caps, proper spacing, page numbers, headers, footers, a copyright page (if you don’t have one), the title pages, and all that stuff. I just need your final text in plain fashion.
I prepared a sample 3-page document that also addresses a few other FAQs about handling your content. Download the submission guidelines sample file here. It was constructed in Microsoft Word in order to keep it real. 🙂