I am not sure if your receiver or DVR is internet capable. So figuring that out is the first order of things to do. There are set-top boxes that have internet capability. So does PS3 and most recently LCD TVs. I think HDMI1.3 standard mandates that all devices be internet connectivity compatable.
If you have sorted that out then you need an answer to the question that you have posted. You can go wired or wireless. But I would highly recommend going wired since the video and audio data from the internet to your DVR or receiver will lag if you dont have a permenant connection. In my case, I connect my PS3 wirelessly to the internet and it always conflicts with my laptops IP adress and the connection gets cut off.
For wired, either run a network cable from the cable modem to the reciever.
Or, bring the cable modem close to the receiver. I take it there is a cable outlet close to the TV
Or, buy the device that sends ethernet over A/C outlet. I think it costs about 40 bucks. You can plug the ethernet cable from your modem to the A/C outlet and tap it from any other A/C outlet in your house.