If you search around the forums you will see that this question has been answered many many times. I really do not want to post a whole bunch of stuff because I have probably posted answers to this elsewhere. But Omega drivers are very nice. A new set was just released yesterday.
www.omegadrivers.net
I use ATI Tool to find my max mem and core speed. I use ATI Tray Tools for more tweaks and game profiles. ATI Tray Tools is very very nice. If you use the search function you will find so much more. Use driver cleaner pro to get rid of all the excess garbage that is left from the normal uninstall process.
http://www.drivercleaner.net/ Make sure you read the instructions first though. Use ATI Tool to find max speeds. Create profiles for games with ATI Tray Tools. Search the forum and you will find so much more.