If you want your PC to network wirelessly, you will need either a WiFi PCI card or a USB WiFi adapter for the desktop computer. This hardware is only necessary if the desktop computer is deployed in a location away from the broadband modem | wireless router and you intend to connect to your home network wirelessly from the desktop.
USB WiFi adapters are relatively inexpensive (approx. $29.99-$49.99, depending on signal strength rating) and i would recommend purchasing one. It will always come in handy as a backup network adapter for a PC or laptop in case your hardline connection fails, your Ethernet NIC fails, or your cable somehow becomes unusable. Besides you might one day decide that you want to move the desktop computer to another location and you just don't have long enough cabling to wire your LAN - the USB WiFi adapter will come in handy then.
However, if you want your PC to connect to your wired LAN via Ethernet connection, you will need to ensure that you have Cat-5 cabling that is long enough to connect: (a) the desktop to the WRT54G wireless router; AND (
the WRT54G wireless router to the broadband modem.
Don't forget that once you have the WRT54G wireless router configured and your wireless network is setup, change the administrative username and password on the router's administrative maintenance page. This page is usually located at:http://192.168.1.1
Hackers know this stuff already, they know the default administrative username and password, so do yourself a favor don't leave the backdoor open for them...