Ringtones and Notifications for BlackBerrys are actually a little bit complicated to setup and change. I've heard that the new Operating System (5.0) will make things a lot easier. For now, you have to go to Profiles, scroll to the bottom, select Advanced, highlight the profile you want to edit and click. This will bring you to a list of all the ringtones and notifications you can change.
Among other things you can set it to vibrate and tone, just tone or just vibrate, set the volume and you can change it up for when your Berry is holstered and unholstered.
Now, to setup a custom ringtone, so it plays a certain sound/tone when someone calls you:
- Go to your address book
- Select the contact
- Hit menu and select edit
- Hit menu again and select Add Custom Ring Tone
- Browse to whatever ringtone you like and select it
- Now when they call, it will play that sound instead of your standard phone ringer
The best place to find free ringtones is trusty CrackBerry.com.
You can find the ringtones section here: Ringtones.
There are also a few free ones on the BlackBerry help website which can only be accessed with your BB browser. Free BB tones