Raspberry Pi - easy to install

sudo nano / etc / network / interfaces

Car Lo
iface lo inet loopback
iface eth0 inet dhcp

auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-ap-scan 1
wpa-scan-ssid 1
WPA SSID "Your wireless NAME" (without ")
WPA-PSK "Your WLAN key" (without ")

save with Ctrl + O, and then exit.
Finally:
sudo service networking restart

I nutz no screen, I had to do it over putty. But should hammer out a beginner.