This is probably fairly elementary for most experts here, but I've written up the detailed steps that can create an automated freeware PDF distiller for Classic apps, using Panther's built-in Folder Action scripts. Full details at this WordPerfect for the Mac support page.
The details that refer to WPMac are easily adapted to any Classic app, I think.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040308123131288