Quote from Sam Morgan:
(See each question)
I am not clear on your situation and what you want to do. How is your desktop connected to the router now? When you said "modem", is it a cable modem? DSL modem? (God fobidden...) 56k modem over a phone line?
The best is hard-wired connection with RJ-45 cables. But with today's technologies, the wireless 300N wifi router works very well too. That's what I am using. 300N Dual Band router. The throughput to my desktops can be as high as 18Mbps through wifi, which is almost the same as a wired connection. If running a CAT5/6 cable deems difficult, you can consider the wifi solution.
RE: 1) I'm ok with plugging the ethernet male to the router female. What happens at the plate end? Would I use a female to female coupler (as shown below) at the plate and have the ethernet male plugged to one side of the female-female coupler (from the inside)? This would leave the other female exposed to the outer face of the plate to which I would have another male-male ethernet cable; one end plugged at the plate and the other end going to the desktop. Would this be correct?
I am totally lost on this question. What is a "plate"?
RE: 2) How do I fish wires up and down the wall (never done it before; handy work inclined

)
Usually you drive a small hole (about 1/2 inch to 1 inch) and use a fish tape to pull wires. When done either cover the hole with a plastic plate or patch the hole.
http://www.google.com/search?tbm=is...=2922l4544l0l4696l9l9l0l0l0l0l168l808l4.4l8l0
RE: 3) Cat 5 or Cat 6? Prices are roughly the same.
Cat 6 is always better than Cat 5 (than Cat 4 than Cat 3 etc.). It is a measure of how many twists they make when coupling the wires. The more twists per unit length, the less magnetic interference on electronic communications. And obviously the more twists the higher the costs in terms of materials used and the process. If prices are equal (or very close) I will definitely choose Cat 6 over Cat 5. It's a no brainer.
RE: 4) Is this type of connection as good as modem-ethernet-desktop connection?
Again, not sure what "this type of connection" mean. If at all possible, one continuous wire is always better than splitting/coupling. Every time you join, you lose something.
P.S. I am surprised that your contractor didn't ask "Hey... you've got Corona?????" Burp!