Configure your desktop
Appearance
Configuring your desktop has changed a lot between KDE 3.5 and KDE 4. For those updating, a bit of explanation is needed.
Icons
If you want to place icons on your desktop (like "file manager", "web browser" and so on) you will notice this is no longer possible using a right-click. Instead, open a file manager and drag the file you would like onto the desktop. It will appear there as icon.