/etc/network/interfaces

Static wired network interface:

    auto eth0
    iface eth0 inet static
        address 192.0.2.7
        netmask 255.255.255.0
        gateway 192.0.2.254

Static wireless network interface:

auto wlan0
iface wlan0 inet static
        address 10.1.1.60
        netmask 255.0.0.0
        network 10.0.0.0
        broadcast 10.255.255.255
        gateway 10.1.1.1
        wireless-essid linuxconfig.org
        wireless-mode Managed
        wireless-key 4ff38e6e98d6a750f33cdb105e

Dynamic wireless dhcp network interface:

auto wlan0
iface wlan0 inet dhcp
        wireless-essid linuxconfig.org
        wireless-mode Managed
        wireless-key 4ff38e6e98d6a750f33cdb105e