Here are instructions for configuring these devices from K9. I saved their site in a PDF so you can download it, or in case the URL changes…
Routers
This site contain instructions for setting up whole-house parental controls with Netgear routers. The technology uses a service called OpenDNS. Many organizations (like Blythefield) use OpenDNS as a way to provide protection and HR policy enforcement for company-owned computers.
Routers can also be setup to limit internet access:
Netgear
Linksys
Cisco
If you have a different brand, please let me know.
Windows computers and tablets
This document describes Windows Parental Controls features that you can use to limit computer start and end times for specific people.