Linux is user end Unix. the only difference is its free!
http://www.linux.org
http://www.linuxcentral.com
http://www.redhat.com **everyones personal favorite!**
to install linux
make sure your pc will boot the cd rom after your order or burn the iso
in setup make a swap file same size as your ram... so if you got 64mb ram make a 64mb swap file
then make the systems drive
the directory should be set to "/"
and it should be about 1gig+
get partition magic and install it with windows =D