Media converter or network cable to hook to new TV?

I have a new Sony Blu Ray home theater that I am trying to connect to my home network. I assume this is how Netflix will send movies, etc. I have a Linkys wired/wireless router. The manual says to gowith a Ethernet/wireless LAN media converter if going wireless or a network cable if not. I'm not sure what this media converter is? I also bought 50 ft of Belkin network cable which I could also use (up to 1000MBps). Now I have heard that to get good quality and HD, you have to go with better more specifuc parts. So what should I use? Thanks