The ‘Help’ button is located at the far right of the main menu at the top of the page.
When you click on it, you will get a pop up window containing helpful documentation specific to that command. You can also navigate back to the Table of Contents for Help and choose a different command to learn about.
If you do not see the pop up window when you click on ‘Help’, your web browser may have a pop up blocker on which prevents the window from opening.