download here --->
http://www.redhat.com/download/mirror.html
(choose a mirror and go somwhere like
*ftpsite*/rehat/linux/*version*/rh.iso1 -3
sadly RH distro's or any linuz for that matter, aren't as widely sold as MS.
but you can try "www.redhat.com" and get signed there for purchase and delivery. or you can try "www.linuxiso.org", there are also lots of other distro's there but less mirrors...
BTW. mandrake should be good enough for you... or try archlinux...
IMHO, switching from distro to distro when you're still a newbie is very time consuming and often less rewarding(believe me, i wuz one i tellz 'ya). try to be better at one distro first and migrate to another... my first distro is RH changed to Suse, then Mandrake, and RH again cause it's what my company implements at work... but im also trying other distro's on my free time(i really d'nt know why i'm compelled to do it, i just do)... But i'm pretty much stuck with RH right now. and i also would like to warn you about RH's multimedia support is poor(or less than you expect from others) maybe due to licencesing whutever... but some occassional hack or workaround is there(almost all linuz do)... so good luck to yaz'
---regards, Me...