The steps? It's really just a matter of buying the laptops and then connecting them wirelessly to the router using the provided key and SSID which is on a sticker somewhere on the router (while setting up the PC, Windows PCs will ask you for this info as one of the optional steps), and then transferring any data over to the laptops if you're getting rid of the desktop. No need to install any special software to get it working other than the usual assortment of Windows Updates. What I would do however, is change the default wireless security of WEP to WPA2-PSK AES on the router via the desktop, which not only is far more secure but is in fact a little faster due to the way it works. For Wireless N should you so happen to get one of the very new routers Verizon has, WPA2-PSK AES is a requirement.
Anyhow, just remember that for FiOS, I wouldn't suggest running anything bandwidth heavy over the wireless. G won't be able to handle anything higher than 24Mbps on average if you're lucky, and also keep in mind the radio works on a shared bandwidth system (meaning 54Mbps theoretical shared amongst everything on it, less if there's lower speed links) on a half-duplex connection. If one device is eating the bandwidth up or has a slower link, everything slows down.
