2
No, you don't have to.
Just go to "Blocks" and then add a new block as a "Side Blokc - Left", and of course, make it Visible.
Enter "Title", e.g. "Resources"
Then, assuming that your file is called "directory.pdf" and is based in /files subdirectory, in the Content enter following:
<table>
<tr>
<TD id=mainmenu>
<a class="menuMain" href="{X_SITEURL}files/directory.pdf">Directorya>
td>tr>
table>
This should give a new menu block "Resources" with the link to your PDF file.
Of course, you might specify who can see it, for security purposes.