I have a Netgear Wireless-N 300 router. I have a Arris Tg862g. Normally my router would receive an internet signal through my modem. That way I could have multiple devices connected to the internet and I could host servers. Then, someone unplugged my router and reset the modem and router. Now, whenever I connect my router it won't get internet access. I had a friend setup everything for me, so I don't know how to resolve this issue.
If your Arris modem only has one Ethernet please connect that to the routers WAN port.
See if things are working.
If not, you may have to login to the router via its web interface. Open a web browser and type 192.168.1.1 and hit enter. You should be asked for a password. If you have reset the device you may need to enter the default one. It is found in the user manual for that router.
Normally the default settings are fine for most cable users. ADSL users tend the require setting up a login/password in the router that your ISP can give you.
In a pinch and to ensure the modem is not an issue, please try to connect a computer directly to the modem and see what happens.
If you get things working, please change the routers password and wifi codes to avoid issues with other users getting into the system.