CentOS System Administrator Prep by Shawn Powers
Installing, administering, and maintaining Ubuntu Server
This CentOS course is designed to prepare a new Linux system administrator for certification and general skills.
A conceptual understanding of what Linux is, ideally with minimal hands-on exposure to a Linux installation of some sort.
Virtualization software capable of snapshots (VMWare, VirtualBox, etc)
Related certifications: LPIC-1
CentOS is the freely downloadable version of Linux created from the source code of a popular commercial distribution. This course not only prepares a person for entry level system administration itself, but is designed to cover the topics required for certification on the commercial distribution.