If I was to teach Linux 101, I would have the students get free iso's of a few distros like OpenSuSE, Fedora, Slackware, etc. Then have them install and configure them for internet connections, about 50 times each. Then compare them for similarities and differences. It sure teaches you alot to fdisk, format, setup dual boots, and get sound and X going. After installing, use mc (Midnight Commander) to poke around the root filesystem, and look at what the various files do.

As far as using Perl as a complete language as a base to teach systems programming, I think you could do it, as long as you emphasize that Perl is just hiding the complexities of the underlying c based system. Then maybe in Linux 102, start showing c, and how Perl makes it easier. See The Rute User Tutorial