Urrr... Linux IS free
Linux (or GNU/Linux if you want to be picky) as an operating system is distributed under the Gnu Public Licence (v2) - which means that the software (and source code)is free and open. You can use is, copy it, pass it on and pretty much do whatever you like with it (especially mess around with it). If you make changes and then distribute it then you must (under the terms of the GPL), pass on (by including the source code of) any improvements or modifications you make.
Here is the GPL -
http://www.gnu.org/copyleft/gpl.html - quite simple and worth reading.
There are hundreds of "versions" of Linux available for free on the Web - most belong to a few main families like Red Hat, SuSE, Debian etc.
There are thousands of free applications available for download on the Web - anything from office suites to CD burners to compilers to nuclear physics. Most of them are open-source.
There are also a smaller number of non-free applications which are closed-source. These are mostly very specialised apps. - you're free to use these under Linux if you want.
If you distribute Linux you can charge whatever you like for it, $1,000,000 if you want, but there are plenty of free versions so you may not have many takers! You can charge for the CD's, support and documentation, but not the software.
The boxed versions that SuSe, Red Hat and the rest make their money from include support, guides, and documentation.
I'd junk your old Red Hat and SuSe 8 (they're way out of date) and try out a recent release.
I'd suggest Mepis Linux -
http://www.mepis.org/ or Kubuntu -
http://www.kubuntu.org/
Yes, there is life after Microsoft - and considering the drastic licence terms of Vista (only two installs and then you have to buy a new copy, pervasive digital rights management, no virtual machine installations, restrictions restrictions restrictions, etc.) now's the time to switch.