ATI drivers are included in commercial release. Following instructions concern installation on the free release.
First of all, you have to install kernel sources :
$ su # urpmi kernel-source
Then, download ati installer and launch it :
# chmod +x ati-driver-installer-X.X.X.run # ./ati-driver-installer-X.X.X.run
Follow the instructions.
Launch fglrxconfig and answer the questions, in order to generate xorg.conf.