How do i convert red and white speaker ends to regular wier ends or with what device?

I have a nice Sony 5 c.d disc changer, 540 watt J.v.c. with speakers,( the J.v.c. speakers each has 4 speaker wire's coming out of the back and there are 2.) The pioneer speakers each have 2 speaker wire's coming out of the back and finaly i plug my computer into my sterio using a red and white audio caible with a headphone plug end that goes into my laptop so i can listen to napster. I need this to be all one setup but i need some kind of device to combine it all. Wear do i find the cheapest deal on this device and what is its name? [I want to get back to jammin' and e-baying a.s.a.p. so any help is help and i am greatfull. :)]