Every time I have to setup the WIFI in a Raspberry Pi I google how to do it. I mostly remember what to put on the /etc/network/interfaces config file, but I need to check out what goes on /etc/suplicant/suplicant.conf. There are many options. Instead of setting up all posible options, start with this. Chances are it would just work ok.
File: /etc/network/interfaces.conf
auto lo
iface lo inet loopback
auto eth0
allow-hotplug eth0
iface eth0 inet dhcp
auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp
File: _/etc/wpa_supplicant/wpasupplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="wifi-ssid"
psk="wifi-password"
key_mgmt=WPA-PSK
}