OK. Installing the driver is pretty easy and straight forward.
Fire up gslapt and download/install vlati.
Once it's finished, open a terminal and type vasm. Select Super Vasm (enter root password).
You'll be presented with a list of options, select fglrx. This will kick off the ATI installer. Select Install driver 8.56.1 and follow the prompts.
Once it's all finished, you'll finish out the xwindow configuration. Once finished, close all that and you should see the ATI options in the KDE menu.
Whups.. Almost forgot. You can edit your settings by running aticonfig in terminal.