You can add a hyperlink to text, images, documents, files, or to external websites. When you login to the website as an admin, open the editor by selecting "edit content". You have a hyperlink manager in the editor, and the icon in the toolbar at the top looks like a chain link. Highlight the section of the page that you would like to make a link, and click the chain link icon.
You will see a dialog box pop and you will have several options on how to add this link. You have the option to link to a page on your site. You have an option of linking to an external website or resource. You also have the option of linking to a document in the document manager.