Online radio w phone thing.

Please Please Please help!

I am trying to create a online radio station! I am going to do this on my macbook. I want some kind of program that will broadcast my audio, a online radio station. I want it to be free. Now I am a mac person. I have looked around and I can't see to figure out how to do this!! I am going to play a playlist and also I want to have some kind of internet phone line. That can be in a different program. I am want to have a internet radio station where I can have on playlist playing and looping and I will drag in a recording of the person who called. I want it all to be free. Also I need to find some kind of plugin that will only play the audio output of itunes, that is where my playlist will be. Sorry if I am confusing. I just want to get this done and working. Please help me out the best you can. Thank you so much!