I recently delivered a free 5 (half) day workshop on an Introduction to Linux Systems Administration. The information was culled from a range of web sources, classes and personal notes, so all credit to the respective sources. All practicals were tested on a vanilla CentOS 6.5 Virtual Machine on VMWare Player, which is free for personal use.
At the end of the workshop, I asked the participants to describe what they thought of Linux using one or two words, and this was the result:
I'd like to share the PDF version of the presentation and if you have any feedback, drop me a line. It's very much a work in progress and I welcome your contributions!