On the GNOME desktop, to start Yelp directly from an application, either click the button or press F1. Both options take you directly to the application's documentation in the help center. However, you can also start Yelp from the main menu, or from the command line with yelp and then browse through the main window of the help center.
The menu and the toolbar provide options for navigating and customizing the help center, for searching and for printing contents from Yelp. To view a table of contents, click . The help topics are grouped into categories presented as links. Click one of the links to open a list of topics for that category. To search for an item, just enter the search string into the search field at the top of the window.