How can I build my custom nodes

[msamy.earth]

I'm a newbie with MySensors. I did my homework to study the getting started section, building my gateway, sensors and actuators as provided in the examples. and everything works great.

In order to build my custom nodes I've started by the hardware wiring. Now I have 3 custom nodes full of sensors and actuators.
My problem now is how can I use MySensors API. I don't know where to start. I need a resource that helps me to understand the mysterious classes like (MyGateway, MySensor, MyMQTT, ... etc).

[hek]

http://www.mysensors.org/download/sensor_api_14

[msamy.earth]

thanks