What do you mean you ran apt-get update and apt-get install? That Alfa card should work out of the box with BT4 Pre Final.
I'm sure you could have found all of this information on the forums VERY easily... But here it is...
# is the number of the interface. If you're using the Alfa USB device and have an internal card, the Alfa will most likely be wlan1. Determine this through iwconfig.airmon-ng start wlan#
# is the number of the interface in monitor mode. Most likely mon0. The airmon-ng command will give you this information.airodump-ng mon#