Im hooking up a new system for the apartment and I need to know the main things when looking at buying a reciever and speakers. I see recievers that put out more watts and have more channels but are cheaper than other recievers with less wats and less channels. What do i need to look for and then speakers. Im looking at Infinity Primus 360's. When it comes to picking speakers how do i know the difference? I just need to know the basics and eventually I'll learn it all when i form a solid base of information. Thanks.