sudo ifconfig
then look on the left hand side for wlan0/ath0 (it'll be in the same column as eth0)
To connect wirelessly try (as root or add sudo before the commands):
If you don't know the essid:
iwlist scan
and it will output all of the wireless networks it can find.
iwconfig wlan0 essid ""
ifconfig wlan0 up
dhclient wlan0
to get the chipset lspci or lsusb depending on card type should tell you. To tell what module is loaded lsmod.