Inserted tracks into mp3 file, but no tracks appear

I have several 20-30 minute mp3 files that I want to split into several shorter files. I used the Nero 8 Wave editor to add 4-5 tracks, but this does not help. After inserting the tracks and saving (under new name and specific folder) in mp3 format, the only file found there will be the original long file with no tracks even in the file.
Anyway to split the long Mp3 file into several smaller mp3 files

 

Load the mp3 in Audacity, select a clip and export it.
Audacity saves it's output in wav format - if you wish to save as mp3, use the Lame encoder plugin.


http://audacity.sourceforge.net/download/

http://audacity.sourceforge.net/help/faq?s=install&i=lame-mp3

 

Thanks for the advice.
Earlier today, I figured it out. I found that I had to let the full file play all the way to the end and then a "save files" appeared below insert rack. Previuosly I saved after inserting the last track.