Here I am after some studying!
Basically, I have this problem: http://community.linuxmint.com/idea/view/3145
: "Linux Mint 13 Maya does not even see the wireless network. It says "FIRMWARE MISSING!!""
I found the BCM4321 divers I need (altough they are not specific for my distro - Linux Mint "Debian" - 201204 Xfce 64-bit - they are for Ubuntu... don't know if they could work the same..)
I installed them, but then nothing changed. Also, when I go to system>settings>network, I don't find the "wireless icon". :-/
(I have other perfectly working devices connected to the same modem, so I assume it works)
Any suggestion? Sorry for my noobness!
[thanks Emegra for your answer]