When you select a standard component on a form, or a property or event in the Object Inspector, you can press F1 to get Help on that item. You can provide developers with the same kind of documentation for your components if you create the appropriate Help files. 

You can provide a small Help file to describe your components, and your Help file becomes part of the user's overall Delphi Help system. 

See the section Creating the Help file for information on how to compose the Help file for use with a component.