Using Microsoft Word Styles is a way to apply pre-set formatting definitions to blocks of text. For example, you can designate a style called “Heading 1” which formats all of your first-level headings in a particular font, boldface, single-spaced, and centered.
You can insert footnotes or endnotes as needed into your dissertation. You can use the method below, or you may want to explore the use of EndNote. Use this program to store your citations and insert them into Word. They will automatically format both in-text citations and works-cited lists. Put your cursor where you want to insert your new footnote or endnote. On the References Ribbon, in the Footnotes Group, click either the Insert Footnote or Insert Endnote icon. To adjust the settings of your footnote, including the numbering style, when to start and stop the numbering of your notes, etc., click on the Expand icon in the Footnotes Group of the References Ribbon.
You can have your footnotes and endnotes restart their numbering in each chapter. To do this, each chapter will need to be its own section.
See for more information on creating sections. Remember, too, that you can format the style of your endnote/footnote as discussed in the Modifying a Style section.