Here are a couple of useful resources for learning about programming and electronics using the Arduino board:
- A pretty detailed electronics primer using the Arduino from a very cool woman called Limor Fried: http://www.ladyada.net/learn/arduino/index.html
- The Arduino Programming Notebook by Brian W Evans:
http://arduino.cc/playground/uploads/Main/arduino_notebook_v1-1.pdf
This is an excellent primer on the Arduino’s programming language but also contains very simple circuits so you can get your code to do something in the real world.
Today I managed to control the brightness of an LED with a flex sensor.