You may have noticed that Google Docs has added a new ‘Outline’ feature which makes navigating your document much easier. If you are creating your documents using the various ‘Styles’ provided (e.g. Normal Text, Title, Heading 1, 2, 3, etc) then the outline will provide you with your various sections in the outline for you.
Simply click on the appropriate title, and you can easily navigate to the section you’re looking for.
If you don’t want the Outline window present, simply click the ‘x’ to close it. To get it back go to Tools > Document Outline.
For more info on using Document Outlines in Docs see this article in the Google Support Site.