beer-run, here is the text of a "read me first" file I loaded on all the drives where this project was distributed 5 years ago, maybe you can adapt these instructions for use on your site:
All Support Documentation in PDF format is linked to the narrative documents enclosed.
On a PC, Control-Click on a hyperlink to open linked PDF in a new window.
On a Mac, Option-Command-Click on a hyperlink to open linked PDF in a new window.
Support documentation that is not PDF (.mp3, .mp4, .mov) must be opened from the Document Library. All PDFs are also in found in the Document Library as an alternative to linking from the narrative documents and directories.