The Linux Professional Institute has a number of Linux certificates for professionals.
The world’s largest and most recognized Linux Certification. LPIC-1 is the first certification in LPI’s multi-level Linux professional certification program. The LPIC-1 will validate the candidate's ability to perform maintenance tasks on the command line, install and configure a computer running Linux and configure basic networking. The LPIC-1 is designed to reflect current research and validate a candidate's proficiency in real world system administration. The objectives are tied to real-world job skills, which we determine through job task analysis surveying during exam development.
Using their objectives list for LPIC-1 101 and 102 of the Aministartive certifacte, this takes those objectives and links it to freely available information plus my own work.
My intention is to teach myself, and provide some guidance to others.