I have personally been using it for about 4 maybe 5 years now. I started with redhat 9, and moved to fedora core 4, somewhere along the line became an ubuntu convert.
I am by no means a linux expert, but I can also help answer questions.
For those of you who don't know, linux is only the kernel (the brain) of your operating system, meaning any features and pretty eyecandy(compiz fusion) are uhh.. We'll call it "homebrew" almost everything for linux is "homebrew"
which is why it is viewed as a better operating system by a lot of people
In linux there is no C:\ drive instead you have / Which is called your root directory, drive letters actually don't exist in linux.
instead, you have what are called mountpoints, most newer operating systems do all this for you, but back in the day you had to mount it yourself.
it used to be everything was mounted in /mnt but newer linux distro's are putting things in /media (not sure when that change took place)
you also have a home folder this is like documents and settings in windows XP
your home folder has your name on it, and this is like my documents
Linux is mostly 2 letter commands
the 2 absolute most common commands are
cd and ls
you might recognize cd, and ls is actually dir
if you ever see a command and you don't know what it is, type man "command
like man ls
although not as common as it used to be, you will sometimes see files that need to be compiled, and will come in a compressed tar.gz
wikipedia has a good list of commands for dealing with basic linux stuff,
also linux commands are CASE sensitive keep that in mind.
ok I am out of ideas post questions and I will answer them.