To describe a series of Java I2C examples that show how to use the supplied Software.
These examples should run unchanged on all the platforms.
Some experience is required to build these circuits. A real beginner should start with one of the excellent online tutorials on basic electronics.
I2C circuits are best developed first on a breadboard. Start with two or three breadboads and a collection of connecting wires of different lengths and colours. You will also need some components - resistors and leds. Lastly you need some I2C chips. I find the MCP23017 very useful - get several. Download the data sheet for the MCP23017 to get the pin connections. Everything you need is available on the Internet very cheaply.
This is an introduction to I2C and uses the extremely versatile MCP23017 driving a row of LEDs.