I shared a video file a few weeks ago with success...now I can't seem to get an mp3 file to share.  On both accounts I have sent an email to my home email address to see if the "share files" goes through or not.

It is likely that your home email account cannot receive DriveHQ emails. Please check your spam filter settings. It is very often that emails be filtered to the junk/bulk mail folder. Otherwise, you can cut & paste the share notification email and send it from your own email account.

If you share files to a group of people, you might want to consider using Group Account service. With a group account, you can create/manage/delete/reset sub-accounts. You can allocate storage and download bytes to sub-users; you can easily share files/folders to group sub-users.