Okay here we go:
Making ringtones for Iphones
open up itunes and find the song that you want to be your ringtone.
Right click the song and click "Get Info"
A box pops up. Click "Get options" (third heading along the top)
Now, ringtones can only be a max of 30seconds long.
Check the boxes marked "Start time" and "Stop time" and then set the times in there so it is only 30seconds long (you will have to play around until you find a section of the song that you want as your ringtone).
Once done, click OK
Then right click the song again, and click "Create ACC version"
Itunes will then create a brand new file for the new 30second song.
Once this is done, click and hold the new song, and drag it onto the desktop. I would advise putting this file into a folder called "Itunes Ringtones" or something like that.. Go back to itunes and delete the 30second file on itunes, selecting "move to recycle bin".
Now go back to the file on the desktop. Itunes ringtones must be in mp4 format. Right click the file and click rename. and change the .mp3 to .mp4 and click ok. It might bring up some prompts asking if you want to continue, just click yes.
Now double click the file to open it, and bam! Where does it open in itunes? The ringtones section... Sync your iphone and there you go...