There a tonne of ways to go about doing this. I use Sony SoundForge, but it's expensive and likely more program than you actually need. Have a look at MP3DirectCut (unfortunately I haven't been around long enough, so the forums won't allow me to post the url) which is free and easy to use. Likewise, MP3Cutter is another alternative. Short of this, it is possible to dump mp3s into Nero and chop out the parts you don't want. Right click your mp3 in Nero and select properties and then the Indexes/Limits/Splits tab. From there you can zoom in on the song and easily chop the parts you don't want. This will take a little patience, but isn't exactly difficult.