Easy to do. First, look for a Network Neighborhood icon on your desktop. If you don't see it, don't worry -- I'll address that in a minute. If you do see it, right click on it and choose Properties. You will see several different symbols; these indicate services, adapters, protocols and clients. If you already have NIC's installed in the machines, you should see them as adapters. Now look for clients. You want to have Microsoft Network Client installed. If you don't see it, just click the Add button, choose Clients, then Microsoft and Microsoft Networking Client (that may not be the exact name). After you click OK, give it a minute to churn, then it should go back to the original screen and will probably give you a message to restart. Hold off on the restart for a minute. Now look for a protocol called TCP/IP. If not installed, follow the same procedure as you did for the Client above. Now look for services; you will want Microsoft File and Print Sharing installed (this is one service). If you don't see it, follow the procedure above one more time, then restart your computer.
When you are in the original Network Properties screen, you will see 3 tabs; the middle tab is Indentification. Go there and give each of the computers a unique name (you can't have two machines with the same name on a network at the same time), something like PC1 and PC2 will do for this example. Under the computer name there is a box for a group name; either leave this blank or make sure it is the same for both computers.
As mentioned earlier, if you don't see the Network Neighborhood icon on the desktop, go into Control Panel and find the Network icon. When you open it, you will be at the same Properties window you get to by right clicking the Network Neighborhood icon.
After restarting, you need to turn on each machine and find the drives you wish to share in My Computer. Right click on the drive and choose Sharing, then give the drive a share name in the "Shared As" box. You will probably need to restart again after this; go ahead and hook the two machines to the hub before you restart.
If you did everything right, you should now be seeing an icon on your desktop for Network Neighborhood. Double click on it and look to see if you see both computers. Hopefully, you will have the same results on both units. Working on PC1, find PC2 in the network and double click on it. You should see the shared drive you set up earlier. Now right click on the shared drive and choose "Map Network Drive" and mark the "Reconnect at Log On" button, then choose an unused drive letter (I would use something above L) and click OK. Now close the Network Neighborhood and go into Windows Explorer; you should see the shared drive as a drive letter. Just use it like you would a local drive; there is no difference.
Write me back and let me know how things go or if you have any problems. I know this is rather long winded, but I had no choice. Good luck!