Connecting two computers for File, and Printer Sharing.
This is a primer of the topic. The goal is to provide basic knowledge, and point in the right direction. Further reading of textbooks and similar sources, and actual experimenting can achieve comprehensive understanding. The primer covers the use of this hardware with Windows OS.
Option 1: Install Network Interface Card (NIC) in each computer (PCMCIA in the Laptop), and Connected them with CAT5 Crossover cable. (Cost about $25 between Desktops, $45 between Desktop to Laptop). You can connect at a speed
100Mb/sec.
Option 2: Mixed connection. If one computer has NIC) or you want to put one. Get an Ethernet to USB adaptor. You connect it with CAT 5 to your computer, and the adaptor goes to the USB port in the second computer (Cost about $15 more then open 1). BTW: regardless of what they say it is Max 10Mb/sec connection).
Example:
EZ CONNECT COMPACT USB 10/100 CONVERTER.
Option 3: Get a USB Direct Connect Module (this is a USB cable that has a special Network module installed on it).
Connect the two computers through the USB; install the Drivers, and your are Connected. This type of connection supports only the speed allowed by USB.
Example:
6FT USB FILE TRANSFER AND NETWORKING CABLE.
This will cost about $40-$50
The connection is restricted by the Max distance allowed for USB cables. If the two computers, are in two different rooms you will have to resort to other solution.
Important, do not connect two computers with regular USB cable, such a connection may result in frying your computer's Motherboard.
Option 4: Direct Cable Connection, uses printer parallel cable, or COM serial cable. The most inexpensive, but the
slowest, and most
awkward. (Cost about $10).
You can find settings info here:
Direct Cable Connection.
Option 5: Wireless Ad-hoc connection.
The wireless option is similar to option 1. However it can be done without the connecting CAT5 cable.
Two Wireless cards can converse adequately. Most cards' software let you choose between Infra Structure, and Ad-Hoc Mode.
Infrastructure = Card to Access Point.
Ad-Hoc = Card to Card.
For a Laptop you get a plug-in PCMCIA card.
For Desktop, you need either a PCMCIA card with
PCI Adaptor (extra $40), or a USB client Card. Either of these cards has to of good quality to maintain a reliable connection.
The easiest - Option 3
The Cheapest - Option 4
The practical - Option 2
The fastest with elegant look for the future - Option
The most expensive, but "Very Cool" - Option 5 
