It's like any other file or webpage you would want to have on the web. You need a domain name (register.com) and web hosting service. Search google for web hosting.
I think you need to tell us some more. Exactly what do yo want to do? Are you making a web site that is to offer streamming audio. Is there already such a site and you just need to know how toupload your audio track to the site?
Watch out for copyright. I assume you own the copyright to this music. It''s something you made and want to publish on the web?
Actually if your Mac is on the Internet full time you can host the site yourself. All the required server software ships with Mac OSX.
^If you already have webhosting, and a domain name set up, then yes- you can just pop the mp3 file into a directory. Quicktime plugin will automatically play it in the browser. Though this is assuming the person has quicktime installed, and also that they prefer it taking over mp3s in their browser!
But yes if you just toss the mp3 file in a directory like
There are free hosting services like geocities, and such. But they have a cap on the size of files, and the total amount of webspace. One mp3 file would max out your free webspace, in other words. There are lots of good hosting companies out there.