First of all you need Winamp. If you don't have winamp installed on your PC already you are a loser.
Then go to www.shoutcast.com/download/ and click on "Be a Server". Read the instructions, you will need to edit the ini file with your proper configuration. Once you're done, you'll be able to broadcast with VDJ or any source of sound using winamp. Your upload bandwidth determines how many listeners you can broadcast to and at what bitrate.