the best bet is using a different media player like musicmatch jukebox to rip the songs in the first place. i don't like converting from WMA to MP3, because you are taking a compressed file, with it's own inherent losses, and compressing it again, causing other losses. what you will wind up with are songs that sound as if they were saved at a lower bitrate than what they were originally saved. if you go with musicmatch,
here is some good info on how to use it.