There is a free program that I think is somehow affiliated with Sweetwater called "Setmaker". It is a nice little program for organizing catalogues of songs, you can sort by artist, genre, featured instrument, key, tempo, etc. There is space for lyrics I believe but I do not know about mp3 files - you may be able to link to them somehow though.
Cheers,
-MIke
EDIT: YOU can get it here:
http://www.sweetwater.com/download/