Footballfreak, welcome to CFP..
MPT is very easy to use and if you're going with MPT make sure you get the latest version, if you do a search you'll find it here in the Motorola forum..
As far as ringers go, you should edit them to be no longer than 30 seconds, no need to have the whole song, you'll never hear more than 30 seconds of it when your phone rings, sound quality, don't expect much, this is a cell phone we're talking about, and the Razr has a small speaker wich doesn't help much.
Overall it should sound good enough for a ringtone.