Headings and subheadings, in concept, are pretty simple. Think of your paper as a play. For headings, think "Acts." For subheadings, think "Scenes."
Even if the only thing you have for headings is chapter numbers, that will do, and in fiction, that is often the case. But in high school, college, and post-grad papers and theses, which are non-fiction, chapter titles may be of more help, because they announce the chapter topic, and assist the reader in following the flow of the paper.
The point of subheadings is to lead the reader through the chapter, and to simultaneously keep the reader engaged, i.e., interested. Each subheading must relate to the heading, or chapter title. In some cases, you may need "second level," even "third level," subheadings (the main subheading being the "first level"). Chapter headings and subheadings should follow the same sequence and wording as the outline.
Source: DB Shaffer; Dr. Andrew Johnson (www.OPDT-Johnson.com)
MLA Formatting and Style Guide
MLA style specifies guidelines for formatting manuscripts and using the English language in writing. MLA style also provides writers with a system for referencing their sources through parenthetical citation in their essays and Works Cited pages.
Writers who properly use MLA also build their credibility by demonstrating accountability to their source material. Most importantly, the use of MLA style can protect writers from accusations of plagiarism, which is the purposeful or accidental uncredited use of source material by other writers.
If you are asked to use MLA format, be sure to consult the MLA Handbook for Writers of Research Papers (7th edition). Publishing scholars and graduate students should also consult the MLA Style Manual and Guide to Scholarly Publishing (3rd edition). The MLA Handbook is available in most writing centers and reference libraries; it is also widely available in bookstores, libraries, and at the MLA web site.
The preparation of papers and manuscripts in MLA style is covered in chapter four of the MLA Handbook, and chapter four of the MLA Style Manual. Below are some basic guidelines for formatting a paper in MLA style.
Here is a sample of the first page of a paper in MLA style:
Writers sometimes use Section Headings to improve a document’s readability. These sections may include individual chapters or other named parts of a book or essay.
MLA recommends that when you divide an essay into sections that you number those sections with an arabic number and a period followed by a space and the section name.
If you are only using one level of headings, meaning that all of the sections are distinct and parallel and have no additional sections that fit within them, MLA recommends that these sections resemble one another grammatically. For instance, if your headings are typically short phrases, make all of the headings short phrases (and not, for example, full sentences). Otherwise, the formatting is up to you. It should, however, be consistent throughout the document.
If you employ multiple levels of headings (some of your sections have sections within sections), you may want to provide a key of your chosen level headings and their formatting to your instructor or editor.
Sample Section Headings
The following sample headings are meant to be used only as a reference. You may employ whatever system of formatting that works best for you so long as it remains consistent throughout the document.
Level 1 Heading: bold, flush left
Level 2 Heading: italics, flush left
Level 3 Heading: centered, bold
Level 4 Heading: centered, italics
Level 5 Heading: underlined, flush left
Source: Russell, Tony, Allen Brizee, and Elizabeth Angeli. "MLA Formatting and Style Guide." The Purdue OWL. Purdue U Writing Lab, 4 Apr. 2010. Web. 20 July 2010.