First you need to install the Graphics driver, it sounds as though you have an ATI card so this is best done using EnvyNG. Open a Terminal and submit this command :
sudo apt-get install envyng-gtk
Once you have installed EnvyNG go to System Tools and run it. Install the ATI driver using Automatic Hardware Detection. When the Graphics driver is installed restart your computer.
Once you have restarted Open a Terminal and submit the following commands :
sudo apt-get install compizconfig-settings-manager
sudo apt-get install emerald
Go to Desktop Settings Manager in preferences.
1. Click on general options at the top select the Desktop size tab, you will see that the Horizontal Virtual Size is 2 increase that to 4
2. Go back to the Desktop Settings manager interface and select Desktop Cube and enable it.
3. Enable Rotate Cube.
4. Enable Expo.
5. Enable Viewport Switcher.
6. Enable Cube Reflection.
7. Enable Animations.
There are loads of tools and plugins which I have not mentioned above in the Desktop Settings Manager so you can customize your Desktop no end.
Also you will find the Emerald Theme Manager which is a must with Compiz Fusion as it enhances the experience immensely.
Visit here to find out much more about Compiz Fusion http://wiki.compiz-fusion.org/
This installation guide of the Graphics driver I have written only applies to ATI cards. If your card is not Nvidia or ATI I don't know how I can help out.
LUg.