You have to have ringtones in order for them to show up in iTunes. The way I used to make them which I havent done in awhile is pick your song. Make sure it is in .m4a format. Copy it to your desktop, open it in QuickTime cut it down below 30 seconds I usually do 28 or 29 to be safe. Save it is as an .m4a file. Ten change the extension on the file from .m4a to .m4r. Drag it into iTunes and voila a ringtones folder should appear with your newly made ringtone. There may be easier ways to do this now but that's how I've always done it. I used to have an Automator script to do it for me but not sure where I put it.