Linux is a ["Unix"]-like operating system kernel that was developed by ?LinusTorvalds and released under the GNU ["GPL"]. The word "Linux" is also used to refer to operating systems based on the Linux kernel; however, the ["GNU"] Project (as well as ["Debian"]) prefers the term ?"GNULinux".
See:
http://www.pclab.uni-bk.ac.yu/linux/ewtoc.html Using Linux
http://dsl.org/cookbook/cookbook_toc.html The Linux Cookbook: Tips and Techniques for Everyday Use
(Please relocate somewhere appropriate - I didn't find anything suitable right now.)
There is a Linux banner-exchange called "?LinSwap":http://www.linswap.com/.