When connecting your AVR-1706 to your LG TV, you will most likely be limited by the connections on your AVR-1706 as it does not have any HDMI capability.
In this case, depending on your LG TV, you would get the best video performance by using the component video connections from your TV to the Receiver. These are the one labeled Y, Pb, and Pr. These are special cables and you will need 2 sets if you want to run video out of your TV (perhaps you are using the internal tuner). Refer to page 6 of your AVR manual for the TV video inputs. Please note you will only use one type of input such as Component, S Video or Composite (descending order of performance). You must connect the Video Out from your AVR to the back of the TV's Video In as shown on page 6 as a minimum to get signals from devices other than the TV.
On page 12 of your AVR manual you can see the connections for TV outputs including the audio connections to the AVR. In the case of audio, you can either use Optical Digital (Toslink) out from the TV or coaxial (RCA) cables: Again in descending order of performance.
If you don't have the AVR-1706 manual handy, you can see it at the following link: http://a248.e.akamai.net/pix.crutchfield.com/Manuals/033/033AV1706B.PDF