Welcome to “Linux fundamentals,” ….. designed to prepare you for the Linux Professional Institute’s 101 exam. ….. By the end of this series of tutorials (eight in all), you’ll have the knowledge you need to become a Linux Systems Administrator and will be ready to attain an LPIC Level 1 certification from the Linux Professional Institute if you so choose.
Full articles here (source: funtoo linux):
Linux Fundamentals, Part 1
Linux Fundamentals, Part 2
Linux Fundamentals, Part 3
Linux Fundamentals, Part 4