Dell sells a TrueMobile 1300 802.11b/g USB 2.0 network adapter as an option for the 4600. If you purchased that option, then you have everything you need to connect with wireless to your WRT54G. If not, then you'll need to purchase an after-market 802.11b/g PCI or USB adapter for your 4600. For example, see my review of D-Link's DWL-122 USB adapter here.
In either case, use Windows XP's network control panel to connect your 4600 to your WRT54G. I recommend that you start with encryption disabled on your WRT54G and get your 4600's adapter connected first -- you should be able to do that by using just the default parameters. Simply enable the network adapter, use the Windows XP Available Networks control panel to select the name of your WLAN (by default, "linksys"), and accept the connection even though it is not secure.
Once you have that working, you should change the WLAN name (SSID) on your WRT54G and enable security, probably using WPA-PSK. Choose a secret passphrase that is 20+ hard-to-guess characters. Then use the Available Networks control panel again on your 4600 to select your new WLAN's name and enter exactly the same secret passphrase there. Be sure to use exactly the same lower/upper case values, etc.. Now you should be connected securely over wireless. If you fail to connect, follow the illustrated wireless trouble-shooting instructions in your Linksys or Dell documentation.
This was first published in September 2004