Use styles, not manual formatting, to create your document's look. In general, document styles should have paragraphs set for one-half inch first line indent, single spaced lines and font set to 12-point Times New Roman or its equivalent. Use Header 1, 2, etc. styles to format all titles and section headings; this makes it simple to go back later and automatically generate a table of contents. Also, set your page size to between 5 inches by 7 inches and 6 inches by 9 inches.
Remove manual indentations and manual double spaces between paragraphs if any are in your book. In Word, go to the search-replace function. Search for "^p^t" (no apostrophes) and replace with "^p" to eliminate manual indents ("^p" is the paragraph code, and "^t" is the tab code). Replace manual double spaces by searching for "^p^p" and replacing with "^p". In WordPerfect, you'll have to go to search-replace, click "Special," and select the specific codes.
Insert page numbering. The acceptable positions are centered on the bottom of each page, or in the upper outside corners of facing pages (so the page open to the left has a number in the upper left, the one on the right has a page number in the upper right.) In WordPerfect, these are simple options on the Format Page menu. In Word, you'll need to double-click on the header, then choose "Different Odd and Even" in the Design submenu of the Header/Footer Tools menu, and format the left and right page numbers separately.
Create a front cover. Your front cover, the first page of your document, can be plain or artistic, but it should include your title and name in a prominent position. Insert this cover as the first page of your document, with one empty page after it. Now insert another page with the title of your book and your name as author centered on the page. Insert a fourth and fifth blank page behind the title page.
Create your table of contents. Modern word processors generate these quickly and easily if you've formatted your manuscript so that chapter names and section headings are in the Heading styles. For Microsoft Word, at the top of your new fifth page select "Insert," then "Reference," then "Index and Tables," and choose Table of Contents (in later versions of MS Word, this command has been moved to the "References" ribbon.) For WordPerfect, look for this command in "Tools," "Reference." The table will self-generate from your text. To update, right-click the table and select "Update."
Convert your document to an ebook format. If you're selling it yourself, convert it into several formats, testing each one. At minimum, you should have a PDF and a text format. Save your document in the native format and as an RTF file before you continue.
Newer versions of Word and WordPerfect allow you to save a document directly to PDF. If you have an older version, your best bet is downloading OpenOffice (a free program), opening your document there, and saving to PDF. Because a text file will lose most of the special formatting you just inserted, go ahead and save your original file as a .txt.
Other file formats you should consider include Mobipocket (.mobi) and HTML. However, if you have a text file and a PDF file of your book, everyone should be able to access your book.