ESP8266 connection to a Arduino Nano

I am trying to connect a WiFi module (ESP8266) to a "funduino" development board (Arduino Nano) but I have no success.

Since I tried so much schematics I've found on the internet about the connection between them two, I kindly ask here if is anyone who succeed in "pairing" this two devices. I am asking for the schematic and a functional source code.


what esp8266 module exactly?