Speakers To Laptop

[m-b]

Was wondering if anyone could help me. I got my party coming up soon and I wanted to buy some new speakers.. But connect them to my laptop. So I play the music from itunes on my laptop, and it comes out of the speakers. Does anyone know how to do it? And also, does anyone recommend any good speakers? I'm not talking small ipod ones I'm talking fairly big.. Also does anyone know how to get audio turntables, from a programme without buying real ones?

Any kind of advice or comments would be appreciated