You can try Audio sharing sites like YouTube meant for sharing mp3 audio files
http://www.imeem.com/ (Popularly known as youtube for Audio)
http://www.esnips.com/ (You can upload mp3′s and even videos and other files)
http://www.4shared.com/ (Easily share mp3′s and other audio files with your friends just like youtube)
Option 2 (Still want to use YouTube ?)
If YouTube is only the way you like to go ! Then Use “Windows Movie Maker” (Comes free with windows XP and later Editions) where in you can import the audio file and add some images (Optional) and export it as a video and then upload on youtube.