which program is best for splicing mp3s'?

Answer 1

Audacity: http://audacity.sourceforge.net/about/features

Answer 2

I use a program called Cool Edit, this is no longer available but it has been bought by Adobe Audition which is a better version of this program. It is an excellent way to edit all your audio files, I use it to record and write my own music as well. It's very simple to use and comes with tutorials for the features that you can't understand right-away.