Private files area for authenticated users

We run a training program. We have the materials that we would like to be accessible only to the students of the program.
I created a page that contains info for the students and I used the content access module to
set up permisions so tha only authenticated users can see that page (the menus are also set up).

So here is the question.
How do I include links in the page like slides.pdf or exercises.pdf etc so that only authenticated
or only users in a particular role can access those resources? I don't particularly need a FILE UPLOAD
module, I can just FTP my files into a directory if needed.
All I need is that only users in a particular role should be able to download that file.

I am knowledgeable in PHP etc so if there is a workaround or something please suggest.

And by the way I am a newbie and I am so far loving Drupal.
Thanks much for your help.