You need some 3.5mm to rca cables. The 3.5mm end plugs into the mac and the other end goes into your amp. Then u get speaker wire which goes from the amp to your speakers. This link should answer all of your questions: http://www.mp3car.com/vbulletin/faq-...tereo-amp.html As for where to get the amp, check out crutchfield or ebay. Make sure the amp isnt too powerful or itll blow your speakers.