Thanks for your reply,
The idea is to be able to manage and control the boiler in my house when I'm not at home,
with 14 digital and 6 analog ports it enables to build in every possible unnecessary features
but like I said, I am a newbie and have many questions 
It might be better to use the Arduino Uno rev3 with the ethernet shield for not having to use the breadboard?
sorry for any spelling mistakes, I'm not so good at English so I write via google tanslate