Create a Logical Reading Order for Sighted and Vision Impaired Users

Page Structure and Headings

Create a logical reading order by using properly nested headings in your markup, <h1> <h2> <h3> <h4> <h5> <h6>.
Build the structure of the page using semantic markup. Markup that has meaning to browsers and screen readers. A web page should be able to stand on its own without the help of a style sheet.
Sighted users often scroll the page quickly and look for headings to get an idea of the structure and content of the page. Screen reader and other assistive technology users also have the ability to navigate web pages by heading structure, assuming true headings are used (as opposed to text that is styled to be big and/or bold). This means that the user can view a list of all of the headings on the page, or can read or jump by headings, or even navigate directly to top level headings (<h1>), next level headings (<h2>), third level headings (<h3>), and so on.
There should only be one <h1> heading per page and should be applied to the page title to indicate to the user that this is where the content area begins.
Headings should be structured in a hierarchical manner.

Proper Nesting of Headings

<h1>Page Title</h1>
      <h2>Heading Two</h2>
            <h3>Heading Three</h3>
            <h3>Heading Three</h3>
            <h3>Heading Three</h3>
                  <h4>Heading Four</h4>
                  <h4>Heading Four</h4>
      <h2>Heading Two</h2>
            <h3>Heading Three</h3>
            <h3>Heading Three</h3>
            <h3>Heading Three</h3>
                  <h4>Heading Four</h4>
                  <h4>Heading Four</h4>
      <h2>Heading Two</h2>
            <h3>Heading Three</h3>
            <h3>Heading Three</h3>
            <h3>Heading Three</h3>
                  <h4>Heading Four</h4>
                  <h4>Heading Four</h4>

Provide Descriptive Headings and Labels

Help users understand what information is contained in Web pages and how that information is organized by providing descriptive headings.

When headings are clear and descriptive, users can find the information they seek more easily, and they can understand the relationships between different parts of the content more easily.

Descriptive labels help users identify specific components within the content.

Labels and headings do not need to be lengthy. A word, or even a single character, may suffice if it provides an appropriate cue to finding and navigating content.

Lists

HTML lists - <ul>, <ol>, and <dl> - also convey a hierarchical content structure.
Lists should be used to display actual list items. They should not be used for layout purposes.