Wireless to my audio system ?

I would like to try using my Mac and streaming it to my audio system for music stations broadcasting on line. I have not looked into stream rates nor how this stuff gets from one place to another, verses sound. My question being... What products are out there, that DOES NOT cost an arm and a leg to get started to see if I even want to go this route. Currently I am using AR pre-amp and Krell amp. Thank you for any suggestions you folks may have.
regards, Dave