I have the same that I got about a month ago. There's a Break-In DVD you could use, I did at first, then said forget about it. I have my set with Cinema Mode and turned the brightness down a bit. I try to keep to full screen programs, though not always, and have limited my game play some. As long as you keep a full screen picture without having a static Image on screen in the same place for HOURS or day after day, you should be fine. You shouldn't have to worry about any burn in, maybe a little Image Retention if anything that will go away. I haven't seen any IR yet.
Bigger things to worry about is making sure your using the right type of Video cable to get a HD picture! The only way your going to get a HD picture from one of the Inputs is from a Component Cable(RED,BLUE,GREEN) or from a HDMI cable, or even VGA if you have to. I did for my Xbox 360 until I sold it and got a new one with a HDMI port.
Also because of DRM in HDMI called HDCP, you can only get a Stereo output from the Optical port of the HDTV. SO if your going Surround sound, connect the Optical directly to your Receiver, if not enough ports, you need a HDMI switcher with Optical ports. Of if you have a Receiver with a built in HDMI switcher, you can go that way.
So really, to me Video and Audio is more Important really to worry about then Break-In. If it was really such a issue, they would include a break-in DVD and warning to run it for 100 hours, but them don't and most people just start using them right away with no problems. It's only a fraction of people that come here and ask!