Wireless configuration on embedded Linux systems has been pretty well documented for a while now. If you are running a Desktop version of Linux then the probability of your wireless device being supported (either natively or through the WindowXP visualization layer NDIS) is likely to be transparent to you. The situation is slightly different when you enter the embedded side of Linux where non-native driver support is really not an option. That said, I have fallen in love with the Edimax Technology wireless USB nic (it uses the RealTek chipset) because they are smaller than my thumbnail, work with any Linux distribution you can think of (even Raspberry Pi), and cost about 10 bucks. Heck, they even support 802.11n. To get this thing enabled/working on Debian from the command-line has been pretty simple.
apt-get install firmware-realtek
ifconfig wlan0 up
Then iwlist wlan0 scan will show you a list of the available wireless networks. Basically apt-get download the drivers, modprobe installs the the drivers, ifconfig turns on the wireless device (otherwise you get a wlan0 Interface doesn’t support scanning : Network is down when you try to scan the. Not exactly the best error message, but anyway…