If you want to use the documents module to place audio (i.e. mp3) files on your site, you need to do the following:
1. Allow mp3 (or whatever) files to be uploaded. Login as host, and in the host menu, select "Host Settings". Locate "Advanced settings", then in there find "other settings", and add "mp3" to the list of file upload extensions.
2. Upload the mp3 files to your portal using Admin->File Manager.
3. Create links to your mp3 files by creating a documents module instance, and then use "add new document" to link to your mp3 files.
Hope this helps.