Whoooo there...
hold on a minute...
if you only want to connect 2 pc's then the cross over cable that you heard about is a good idea.
but I can understand why you might like to do it properly... however this does not necessarily entail a router!!!
You were right in your first post the equipment that you require is called a hub.
for the purpose of connecting 2 pc's there is no need for a switch, and definitly no needfor a router!
Firstly...
How the cross over cable works...
In the network socket there are two lines, (well theres four actually but 2 are unimportant for this).
One is send (Tx) and one is recieve (Rx)
all a cross over cable does is swap these about so that the send of the first computer is conected to the recieve of the second, and the recieve of the first computer is connected to the send of the second,
ie
Code:
----------
Tx(A)-----\ /-----Tx(B)
- X
Rx(A)-----/ \-----Rx(B)
(the X is the cross over!)
A hub is a little more complex, but basically the same,
in all the hub is basically a dumb piece of hardware, it listened for tramsmission (Tx) signals on all the ports it has, and when it recieves one it copies that signal to all of the recieve ports of the machines connected to it.
a hub will (usually) let you connect more than two pieces of hardware to it, and so can be used for sharing an internet connection if you have a modem with a network socket on it, or if you have a USB modem and need another computer to connect to the internet, also a hub can be used to share files and printers.
Next a switch...
a swith is basically an intelligent hub, it listens to all the transmission signals, but instead of repeating what it hears to all the devices attached to it, it only repeats it to the device that needs to have the information.
(Imagine how much slower your network is if someone downloads a 3GB file and all the bits of the file are sent to every computer on a hub (subsequently ignored), but still clogging up bandwidth!
Next routers, (and specifically why you don't really need one).
Routers can be thought of as super intelligent pieces of equipment, and usually have either a dumb hub, or switch attached to them.
Routers are normally used to conect to the internet, or to connect different nodes of the internet, the job of the router is to monitro traffic activity as information is sent through different nodes on the internet and try to determin the best route for the data to travel... (hence the name router!)...
However since you are only talking about using two machines, what exactly is a router going to decide? how will it improve your situation?, I see little point of you investing in a $60 router, when a $10 hub would suffice just as well..
Lastly, accessing your files, only those files that are actually shared are acessible, but that is not to mean that you don't have some hidden shares you don't know about...
to find out what shares you have on your machine open the command prompt and type
net share