Step 1: Go to the Content Item that you wish to add the relationship on. (Example: You want to relate an image to a new or existing News Item)
From the top navigation, click on Content drop down and then News Items, Search for an existing News Item or create a new one. This will bring you to the Create/Edit News Item Dialog.
Step 2: Select Documents.
Under Related Media section, click the Select documents button to bring up the documents upload/select dialog.
Step 3a: Choose a document from Recent Documents or Show all documents.
Clicking the plus button will show a list of recent documents. If the document you wish to link to is not visible here click o the 'Show all documents' link to bring up a complete list.
Step 3b: Repeat step 3a as needed.
Step 4: Re-order the Documents (if necessary).
To reorder using the mouse select/click/hold and drag the item to the new place on the list.

Note: To remove a Related Document click the x button.

Step 5: Publish.
Click the Publish button to save the changes.