Ethernet is available in two speeds: 10 Mbps and 100 Mbps. Most NICs are capable of operating at either speed, but you should check to be sure before purchasing. Get cards capable of the 100-Mbps data rate -- the difference in cost is minimal. A 100-Mbps card costs about $15 to $40, and a 10/100-Mbps card costs about $25 to $50.

There are two different ways to connect Ethernet cards: coax and Cat 5 cabling. Coax was once the more popular of the two, but today just about everyone uses Cat 5 because it is easier to configure. Cat 5 has a cable that looks a lot like a telephone cable. You run one cable to each computer, and each cable connects to a hub at the other end. A basic hub for a home network is a small box that typically costs from $25 to $50 (depending on its speed and how many connections it can support).

To connect more than two computers using Ethernet, you will need a hub like this.

The hub takes the signal from each computer and sends it to all of the other computers in your home. Hubs come in several sizes, noted by the number of ports available -- a four-port hub can connect four computers, an 8-port hub can connect up to eight computers and so on. Most hubs are stackable. A stackable hub has a special port that can connect it to another hub to increase the capacity of your network. So if you start with a four-port hub but eventually have five computers, you can buy another four-port hub and connect it to the one you already have, increasing the potential number of computers on your network. A cable/DSL router usually has a four-port Ethernet hub built in.

To connect the computers, you will need Unshielded Twisted Pair (UTP) Category 5 cable. This type of cabling is designed to handle the 100-Mbps speed needed by Ethernet. The RJ-45 connector at the end of the cable looks very similar to the RJ-11 connector on a phone cord but is slightly bigger (and not compatible). You can buy Cat 5 cables in predetermined lengths with the connectors already attached. If you plan to install the Cat 5 cabling in the walls of your house, you can buy the cable in rolls, cut it to length and connect the cable to special RJ-45 wall boxes. Unless you have done this type of installation before, you will probably want to hire a professional.

Because of the large number of possible configurations in an Ethernet network, you most likely will not have any type of automated installation software. This means that you will have to manually configure all the options as we discussed at the beginning of this article. If you have problems, the best source of information is probably the manufacturer of whichever NIC cards you decide to use. For more information, see How Ethernet Works.

If you don't mind running the cables along the floor, you can install an Ethernet network for two computers in your home for $100 or less. That includes the cost of two Ethernet cards, a small hub and two cables. Each additional computer will cost about $30 to $40 to connect using inexpensive network cards.

*Note: If you want to connect just two computers, you can avoid the hub and use a crossover Cat 5 cable. With a crossover cable, you directly connect one NIC card to the other without a hub. This only works for two computers -- to connect more than two you need a hub.