Personally I think using a text editor to set up wireless on Debian is the easiest way.
The network configuration file is /etc/network/interfaces.
For wireless you need to install "wireless-tools" and "wpasupplicant"; if you have a console open: apt-get install wireless-tools wpasupplicant
There are numerous posts already on how to set it up and you can also find some tips in /usr/share/doc/wpasupplicant