Adding a security camera system to my home

Ok so there has been a uptake in the number of car break-ins, porch thefts etc in our neighbourhood. I want to add a wired security camera system using my tv to view what was recorded. I do not wish to use "the cloud " as storage. I will use a NVR. I am certain I can run the cables, and make all the necessary connections to the NVR, cameras, and tv. I am not certain what to do after that. Everywhere I read it says to connect to your router. I have a Telus t3200m modem, and was hoping to be able to use that. I will likely use a powerline adapter. My main question is-- Do I need a separate router? It should be obvious that I have never done this before. Ha Ha.