The Raspberry Pi Model A+ has just a single usb port, so getting the wifi configured has to done by editing /etc/network/interfaces from a command line prompt.
These instructions assume the Raspbian OS on the SD card, and a usb wifi adapter that supports the RTL8192cu chipset, since the current Raspbian has built-in support for it.
Before the first boot
- Put a keyboard in the usb slot
- Connect the HDMI slot to a monitor