The problem with ARC is it is usually going to give you stereo (widely discussed why) so be sure to discuss that if you must. In short you should find the connections should be from source to HT then to the HDTV. Other setups tend to go badly as folk discover (again) stereo over ARC.
I am having trouble getting my new D8000 TV and HT-D6500 to talk to each other using Anynet+ (HDMI-CEC) and ARC. I have tried all combinations of settings I can think of but I cannot get sound to the home cinema amp from the TV tuner, nor can the TV discover the amp to use Anynet+. I have set up the connections per the amp's manual, with HDMI connection from the amp's HDMI Out to the TV's HDMI In 2, which is the ARC enabled HDMI port. The instructions seem contradictory as to whether I also need an optical digital sound cable - I don't have one long enough to try it, but the whole point of ARC is to carry the sound over HDMI. I can use the amp with the Sky box, which is also connected to it by HDMI, or with a disk, and the amp passes the picture to the TV. I have tried turning on Sound over HDMI and switching the TV sound setting between internal and external speakers. Anynet+ is set to Auto.
What settings are essential on both devices to use Anynet+ and ARC? And what connections are needed - do I need an optical link, or perhaps a second HDMI cable?