How and where to learn Linux?

I'd like to pass some exames to get certificates for Linux. Can someone advice me how to do it "on distance" and self studie?

thanks!
d.

Try running a search on this website. The question has been answered many times in the the past.

All you will be using in Linux if your an advance user is the command line (shell). You should look up some shell commands and learn therm. If you plan to do anything else it would be all self explanatory. Enjoy Linux! ;D

Yeah, OK thanks! But I'd like to find docs about Hardware for Linux, Software Products & Solutions, Diagnostics, Internet & Networking etc. similar like this: http://docs.hp.com/ or step by step for learning before exams. Is this possible for Linux somewhere?

May be you are interest on IBM LPI documentation
LPI 101 certifcation

Part 1: Linux fundamentals
Part 2: Basic administration
Part 3: Intermediate administration
Part 4: Advanced administration

LPI 102 certifcation
Part 1: Compiling sources and managing packages
Part 2: Configuring and compiling the kernel
Part 3: Networking
Part 4: USB, secure shell, and file sharing

And guides from
Linux Documentation Project