Just as in a normal web browser you can click on the blue hyperlinks to jump to different sections.
The toolbar at the top provides additional navigational facilities:
Use the home icon to return to the help contents screen at any time. Use the backwards (left facing) icon to go back to the previous page visited. If you go back one or more times you can then use the forwards (right facing) icon to go forward again.
The Location field displays the URL of the file currently being viewed.