In most cases, you'll find the information if you do man <your card>. For example, with the Intel 2100 or whatever it was, I would do man ipw (I think--I don't have that machine anymore) and it would give the information.
For example, here is an entry from the ipw man page.
Join a specific BSS network with 40-bit WEP encryption:
ifconfig ipw0 inet 192.168.0.20 netmask 0xffffff00 ssid my_net \
wepmode on wepkey 0x1234567890 weptxkey 1
So, there's your syntax.
Youve probably realized it already, but rather than the generic eth0 wlan0, FreeBSD will use something based on the particular card, such as fxp0, xl0, etc.
Yup, I just checked man ral and it has several examples in there too.
Were you using one of the Linux GUI tools, such as NetworkManager? It is a bit different, (although perhaps Gnome or KDE in FreeBSD also has such tools, I don't know.)
It's always good to learn the command line way to do it though. For example, in Fedora, NetworkManager frequently gets broken.
