This is the Google Docs Help article about publishing Google Docs to the Web
The help article says
"Click the Share drop-down menu on the top right of the page and select Publish to the Web...."
What is doesn't tell you is there are minor differences depending on whether the document you are trying to publish has been created using the latest version of Google Docs or an earlier version.
If the document was created using the older version of Google Docs, what you actually see is...