I'm having a problem...

This Friday I'll be having a party at my house because on Saturday I'm going to be 17

Anyway, ALL my music is on my PC and the party is going to be in the living room.. so how can I connect my PC so I can play MP3s on my System that are controlled from my PC in my room...

what cables do I need and what do I need to do????

thanks a lot!
-Emo