The easiest setup is to put in the Wifi Router. It's as much as a WAP. As to streaming audio, then you need something to receive the Wifi "stream" as well as offer a remote control. There are a few devices but some may wonder what they've gotten themselves into as the PC has to be on and more.
Maybe an iPOD to the stereo is a simpler idea? (Or other player.)
I'm a novice at home networking technology. I would like to connect a home theater system in the living room of my house to the PC/cable modem in my Den (30ft) via WiFi in order to get streaming audio. Is this possible? If so, do I need a router, or do I need a wireless access point to make it work?