Problem : "I need non-free softwares for my Wireless card ... (example)"

Solve :
- Edit your sources list with Vi "vi /etc/apt/sources.list"
- Add :
deb http://httpredir.debian.org/debian/ jessie main contrib non-free
deb http://security.debian.org/ jessie/updates main contrib non-free
deb http://httpredir.debian.org/debian/ jessie-updates main contrib non-free
- Save and start your update