I assume you have a working network ?
More than likely the router is providing the IP addresses to all the machines. You technically don't need the address of the router since the data will pass directly between the machines. You also don't need to do any configuration on the router to make it work. You only need to change the router when you want to share outside your house..not a good idea.
So open a command prompt on each machine and issue IPCONFIG. It will tell you the IP of each machine. You also get the router address on this, it should be the default gateway.
Most people use Samba to share microsoft files. Many times this is already installed. People have videos on u-tube showing how to install it.
I want to set up a Home network between a Win XP PRO/LINUX UBUNTU 10.10(Dual boot) and a Win XP PRO.
I need to find out:
A) The IP address of:
1) Each machine on the router
2) The router's IP address
B) How to configure the router using this information
Several years ago I saw a tech set up a network using this information but I don't remember how to do it
C) What software I can use on Ubuntu to set up the network