I noticed your site has a blog which has a built-in RSS feed. My first thought is to use this as your RSS feed and make it a practice to post a blog entry anytime you add new content to your site. I'm thinking the blog content could be an abstract of or intro to your PDF content followed by a link to the PDF. (I'm assuming the content you'll be adding is like the PDF stuff that's already there.)
A blog seems like a simple way to author the stuff that goes into a feed (date, subject, content). You also have the ability to organize your content or separating entries related to PDF content from all your other posts by tagging them.
Do you have a need that the blog approach does not address?