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
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.