First of all you should make sure that we are able to read your question, so that answers are even possible. Please use break tags and such as well, though you know the bold tag already. Wrap your code in code tags. Thank you.

Do you want to display a list of pdf files in a certain directory or the pdf file itself? I am not sure.
For the access problem: This is a configuration problem of you r web server. Maybe you want to add a symbolic link and set the rights in an .htaccess file. (I am persuming that you use apache if not, have a look at the documentation there). You may want to look at apache's website to look up the right settings.

Perl related stuff: Whenever you want to output some html stuff use cgi. Try to run a search on cgi on this site. It will give you tons of nodes to look at. Also try perldoc CGI at your command line.

Hope this helps,
C-Keen

P.S.:This answer may seem a bit harsh but this place is not for doing somebodies work, just to learn how stuff is to be done. To do so you have to fiddle with it yourself

Update: Thanks kudra for reformatting