I've made a package of the Itasca example that are supposed to work "out of the box" for Debian Lenny and Squeeze. I intended to push it in the repositories, but due to lack of time, I gave up on the idea. So instead I put the tar file here. You can download it. And unpack it your /var/www directory. Accessing localhost/mapserver you'll find the itasca examples working (at least, I hope so...).
Of course you need to install before hand the packages of apache2 and cgi-mapserver.
So, with out further a due - here's the tar file: [ad#banner]
Download, and untar in /var/www.
Access localhost/mapserver from your browser. Now you can start exploring MapServer.