There are a variety of methods for making digital documents easy for users to navigate.
Headings
Headings and subheadings play a key role in navigation and should form an outline of the page content. This enables screen reader users to understand how the page is organized, and to quickly navigate to content of interest. Most screen readers have features that enable users to jump quickly between headings with a single key-stroke. For more information about this technique, see Headings in documents.
Bookmarks in PDF
PDF files should have bookmarks for lengthy documents. These enable all users to efficiently jump to a particular chapter or major section. Before adding bookmarks to a PDF, be sure the document is tagged and has a good heading structure, as described above. For more details about tagged PDF, see Checking PDFs for accessibility page.
After you have a tagged PDF with good structure, select Bookmarks from the Navigation Pane in Adobe Acrobat Pro. Then select “New Bookmarks from Structure…”. A dialog will appear showing the various structural elements that are used in the document. Select H1, H2, and additional levels of headings if desired. When deciding on an appropriate level of detail within your Bookmarks, try to balance the need for navigation with the need for simplicity. Keep in mind the more bookmarks you have, the longer it will take for screen readers to read through them.