Anyone new to Linux/UNIX CLI (Command Line Interface... i.e. that scary all text thing that you see a lot) should immediately go to
http://www.linuxcommand.org
and follow along with the tutorial. VERY thorough and well explained, and actually walks you through commands that are useful to helping beginners get around in Linux. Also important (including while trying the tutorial, if you come across something you don't understand) while not referring explicitly to Linux is
http://www.wikipedia.com
You can find good explanations of almost any term here, especially computer oriented ones.
NW