NodeMCU is the development board based on the ESP8266 that makes life easier for those of us who want to develop connected devices. In this book we will give a review of the 5 most important points of NodeMCU . This tutorial consists of 5 parts . We started by seeing an overview of the development kits and NodeMCU . Then we will differentiate the different versions that we find of this plate. We will see the pins that are available and their particularities, the LEDs and push buttons integrated within NodeMCU and finally how to connect NodeMCU to our PC . This book will start teaching you from simple "Hello World" using ESP8266 and ends with uploading your Sensor data's such that whole world will see your work.