The ProtoSnap board is a great way to introduce students to Arduino without the need to create circuits because the leads are already connected in the PCB. Teach digital input with the button, digital and analog output with the RGB LED and buzzer, and teach analog input with the photoresistor. Once the concepts are understood you can snap the pieces apart to embed them in a project. The Arduino Pro Mini comes with the Arduino Uno bootloader preloaded so you can even use Graphical User Interfaces to program the microcontroller.
ProtoSnap Sketches (ZIP)
Courtesy of SparkFun