1- That the Netgear router is working ok
and that 2- your network interface card (NIC) is also working ok.
I would use an "ethernet cable" first to make sure both your NIC and your router are working ok.
An ethernet cable can be bought either online with Newgg.com or at a local store that carries computer-type stuff, like Best Buy. You only need maybe 3 or 6 feet, depending on how far your computer is from your wireless router. Worst case scenario, move the wireless router temporarily next to your computer to test it. Another thought is, the tech who helped you might give you a short piece of ethernet cable for free. It's not expensive stuff at all for a short piece.
Once you have bought it or obtained it, plug one end into the back of the computer (it only fits in one slot) and plug the other end into your wireless router (again, it only goes into one kind of slot). The slot on the back of the router will say LAN (local area network, which is you and your router) or Port. The WAN (wide area network or the internet) port is ONLY to go to your modem.
Once you have both plugged in, open up your web browser (internet explorer, firefox, etc).
Type this exactly into your browser address bar:
http://192.168.1.1Hit enter. You should see the router login screen. If not, 1- your router is bad; 2- your NIC card has gone bad; 3- your network configuration inside your computer is not done exactly right or 4- a combination of the foregoing.
Let's assume you see the router login page OK. You have to type in the default username and default password for the router, which is admin for the username and password for the password, per the pages you linked to.
Once you are in the configuration pages, you have to spend five minutes setting everything up. You need to IMMEDIATELY change the default password to something only you know and not a super easy one, like 1234. Something very hard to guess. If you need help, just shout.
ETA: 99 cents for five feet of ethernet cable at Newegg
http://www.newegg.com/Product/Product.aspx?Item=N82E16812120909