You need to review the documentation over at shoutcast.com. Ask your questions there as your questions on this thread will only clutter it with unecessary noise.
Until you get your shoutcast server running, then you really shouldn't be posting your shoutcast questions here.
You can find out your IP address at
www.dnsstuff.com. Yes, you will need Winamp and the DSP plugin in order to broadcast. ALL of this is fully documented at shoutcast, so please ask over there first. You do not need to upload your MP3s to your server. They play via Winamp. Do yourself a favour and read first.