So how do you get started? There are a number of internet sites that will host your music for free. Or you can do it yourself by getting a website that has MP3 streaming capability. The latter will cost you some money, but not much if you look around.

Some free sites that I use are
Check out Google for more.

Having another site Host your Music: How it works

You simply register with them, get an url and password and they will send you back the location of your site and instructions on how to get started. Some let you add your own pictures and text, so you can personalize the pages to suit you. Then you upload your music files. Typically these will be in MP3 format, so some sites will want them in Windows Media format too. You should be able to make these files directly in most major music software, such as Logic, Sonar and Cubase (some may require you purchase a separate plugin). If you don't have that facility you can use a utility like WinAmp or MusicMatch. If you have Apple's iTunes you can use that.
Once you upload the file it may take a day or so to clear. Some sites actually listen to every song to make sure you are not just streaming a long list of profane words. Assuming your are within common standards your music will appear on your site and it becomes accessible to the world. Amazing.

Once you do get your music up on the internet, post the url in a Song Review Forum. You'll have an instant audience.

Looking to make some easy money from your music.
Visit http://www.mymusicsource.com/were your music is reviewed and if its accepted your music will be made available for purchase or use by 3rd parties