Aldis, it sounds like you might do well to read the book "Running Linux".
It often comes with a set of distribution CD's (it used to come with five
CD's that contained all available distributions).

There are several sites that sell inexpensive CD's of current distros,
without documentation or support (they offer that too, for more money).  I
like www.cheapbytes.com, but there are others.  For a couple of bucks and a
few days wait, you can get a very current CD set.

The other thing to do is to hit www.linuxdoc.org and read the HOWTO's.
That's the best real-user documentation that there is.  It's more about how
to get something to work than the man pages, which are about how the
software is conceived to run.

For instance, my video card is a Diamond Monster Fusion.  To Linux, this is
a Voodoo Banshee - real intuitive, eh?  When XFree86 4 came out, the driver
for the Banshee just plain didn't work.  I had to fall back to XFv3.x to
make it work, which cost some other features I wanted in Linux.  I figured
this out mostly by searching for "Voodoo Banshee" and "Linux" on the Usenet
Newsgroups (archived now at google).  This list* and the HOWTOs have been of
similar help.

For me so far, Linux makes a great firewall.  I'll probably build a server
with it this year, and retire my NT4/Exchange 5.5 server - I don't need to
prove my Microsoft Manhood any more.  I've actually booted to Linux once
because it was easier to do something in Linux than in Windows.  I've also
often used Linux for things like nmap and for search tools that just don't
exist in Windows, but last week was the first time I had the option to do
something in either environment, and found that it was so much easier in
Linux that it was worth rebooting.  (What I did was un-gzip an iso image,
and since I would have had to reboot to get back to Windows, I figured out
how to burn a CD more easily than I could have rebooted.  We're getting
there.)

* Unfortunately, if the list manager doesn't get his BUTT in GEAR and set up
AUTHENTICATION, this list is going to DIE from SPAM and VIRUSES.