We Recommend LPI Certification
Chris Collins Client Engineer at Verizon Terremark
LPIC 1 - Cheaper than the Red Hat course.
Kevin Gichohi Applications Developer - AVP at JP Morgan
Great course, exa focuses on Linux, but also contains questions on computer hardware.
Adam Hamflett Head of Computing at Piggott School
Linux Essentials is a great course for anyone wanting to brush up on their informal Linux knowledge or want to start learning Linux for the first time. Highly recommended.