Use a Switch to Add More Ports
Few home networks need more ethernet ports than the four built into a typical router. But small-office networks can quickly outgrow those four ports as additional PCs and network-equipped printers come aboard. Instead of buying more routers, try adding a simple, inexpensive switch. Technically, you could use hubs to split off more ports, but they're clumsy with traffic: They can't simultaneously transmit and receive packets, and that data gets broadcast everywhere. As a result of these traits, packets collide and have to be resent, which slows down your network. Instead, use a switch.
Switches can send and receive data at the same time. Try to buy one that includes enough ports for your needs. But if you run out of room on it, just add another switch. It is best to pick one that uses gigabit ethernet. Even if you currently use 100Base-T hardware, you can grow into the faster speed with new devices in the future. Avoid 10Base-T switches. Installation is simple: Just connect an ethernet cable between the router and the switch, and then connect new devices to the switch's free ports.
Extend a Wireless Network to a Wired Device
If you have ethernet-only devices that you would rather connect to your network wirelessly, use a network bridge instead of stringing cables. The wireless bridge method can work very nicely with an Xbox 360, a TiVo, or other wired devices. Though I prefer the simplicity and speed of a wired network, wireless sure looks more attractive. Here's how to get started.
The process mirrors the wireless router setup. First connect a PC directly to the bridge via ethernet. (Temporarily disable the PC's Wi-Fi if necessary.) Since the bridge won't be broadcasting a DHCP address, though, you'll have to configure your PC's ethernet details manually. Open the Network Connections Control Panel and right-click the Local Area Connection. Select Properties. Double-click Internet Protocol (TCP/IP), and click the radio button for Use the following IP address.
Consult the bridge documentation to see which address it uses by default. Enter an IP address with the same first three sets of numbers but with a different fourth. For example, the Netgear 5GHz Wireless-N adapter (WNHDE111) defaults to 192.168.0.241, so I set the PC IP address to 192.168.0.2. (Pick any number between 2 and 254.) Leave the Subnet mask as 255.255.255.0, unless Windows assigned it a new number. Click OK twice.
Enter the bridge IP address into a Web browser, and connect to its configuration page. Configure its wireless settings to match those of your wireless network, applying the same SSID and encryption details. Leave the bridge set to receive DHCP details from your router.
Restart the bridge, and switch your PC back to DHCP by opening the Local Area Connection again in the Network Connections Control Panel. Double click Internet Protocol (TCP/IP), and click the button to Obtain an IP address automatically. If the PC can get online, unplug the ethernet cable, and attach the bridge to your wired-only device. If you run out of ports, add a switch, just as you would on a wired segment of the network.