Links are used to add a picture file in a template/email. To add a picture in an email you will need to upload the image first using the upload image function (Home - Upload files) and then edit the Template to add the image into the template.
If you are sending a bulk email from the members page you can add an image (see below) before you send it, but you will need the URL stored in you clipboard. see #note1
To add links to files in your emails:
go to Home - Upload Files
Browse and select the file to upload, add a file description and click the blue Upload button
#note 1: The file will be added to Uploaded file list, right click the yellow open button and copy link location
Go to Home - Templates - Edit Template
Highlight the text to link to and press the link button in the toolbar
Paste the file link location in the Url text box and press ok
Save the Template, to save the changes to the Template record.