Step One
Download the Shoutcast Server and install it on your machine. Make sure that you install the GUI version rather than the console version.
Step Two
Go to Start Programs Shoutcast DNAS Edit Shoutcast DNAS Configuration. Read the instructions contained in this file and change any settings that you need to. Depending on your connection speed, you can configure the number of user connections and transmission bandwidth as well as set a password and name for your channel. Close the Configuration file when you're done.
Step Three
Download the Shoutcast DSP Plug-in for Winamp and put it in Winamp's plug-in folder. Open Winamp and go to Options Preferences Plugins DSP/Effects. Select Shoutcast Source For Winamp and click the Configure button. Make sure that all of these settings (especially the password!) match the settings that you chose in the Shoutcast Server Configuration file. Click OK and close the preferences.
Step Four
Put the MP3s that you want to play in your Winamp playlist by pressing the PL button in Winamp and dragging and dropping the files into the Playlist window.
Step Five
Go to Start Programs Shoutcast DNAS Shoutcast DNAS (GUI) to start your Shoutcast server. Hit Play on Winamp to start the stream. That's it. Anyone who has your IP address can now connect to your server and listen to your customized radio station.