Sending the same video to multiple monitors is a common need. Perhaps you are giving a presentation in a large room without a video projector, or your viewers are located in two different rooms. Maybe you are creating a do-it-yourself digital signage system where you are using the same video input to display information on televisions located in two different places. Whatever the need, you have discovered you can't simply split a video signal the way you can with audio cables. Unlike audio, halving the video signal degrades the image quality so that it is unwatchable.
Assess the inputs of your televisions. They should have a common RCA or S-Video input. HDTVs will accept a wider variety of inputs. If you want to maintain the high-definition video quality, you should use the HDMI inputs.
Plug the output of your video source into the video input of your video distribution amplifier. Connect video cables from the output of the video distribution amplifier to the video inputs of the two televisions.
Select the appropriate video inputs from the remote controls of the televisions or using the input selector on the television monitors.
If using RCA style inputs on the televisions, select a video distribution amplifier with RCA outputs. Likewise, S-Video television inputs will require an S-Video distribution amplifier.