I just put them into itunes but I can't use them on my phone..whats the problem?
As was said above by the other member, you simply have to make sure that your iPhone is being told to "Sync all ringtones" or whichever individual ringtones you want. Just click on your iPhone in iTunes, and then when it brings up the main screen with the graphic of your phone, and the phone's serial number, etc. just click on on the "Ringtones" tab, and be sure that the ringtones are checked off. Then when you sync, they will upload to your phone. If the rings were imported into iTunes correctly (literally just drag the unzipped m4r files into iTunes), then they should show up in the Ringtones tab in your phone's properties.
Note: although they might be checked off in the main ringtones tab in iTunes, you have to check them off in the iPhone specific tab, like you would do to upload music to your iPhone. Refer to the attached picture below:
EDIT: I also updated the main page with pictures to aid the instructions, so if anyone is having problems just make sure you follow the instructions as aided by the pictures.