The Mechatronics Handbook, Second Edition
Chapter III: Sensors and Actuators
http://www.kelm.ftn.uns.ac.rs/literatura/mur/IntroductionToSensorsAndActuators.pdf
Making Sounds with Arduino
https://learn.adafruit.com/adafruit-arduino-lesson-10-making-sounds
Driving DC Motors with Arduino
https://learn.adafruit.com/adafruit-arduino-lesson-13-dc-motors
RGB LED Fader with Arduino
https://learn.adafruit.com/adafruit-arduino-lesson-7-make-an-rgb-led-fader