I usually use itunes. You can download it here:

Apple itunes 2

As you're using OS 8.6 and itunes is only designed to run on OS9 or OSX, you'll need to download and run this patch as well:

itunes OS8 patch

For instructions on how to install the patch, go here:

itunes OS8 patch tutorial

If the patch doesn't work with itunes 2, you can try itunes 1.1 whose link is on the patch tutorial page.

I suggest you move your mp3s out of the shared folder and classify them in other folders by genre or group, for example. Once you have itunes up and running. Go to the file menu and select Add to the Library. Select the folder(s) with your mp3s in the file selector that appears. They should now appear in the playlist.

Good luck and happy listening!