How to begin with Arduino?

There are several books which help you a lot to learn Arduino from beginner to advanced level such as:

A- a main book which is consist of three parts in English as follow :

    Book 1 : Getting Started with Arduino.

    Book 2: Getting Started with sensor.

    Book 3: (FUN)! Arduino Bots and Gadgets.

B- Simply Arduino (in Arabic)

C- كتاب القرية الهندسية - احترف الأردوينة

You can go to web site arduino.cc to know how developpment and creat code arduino 

START->ARDUINO IDEL->FILE->NEW   

CAN I TAKEN THE EXAMPLE OF THE PROGRAM SELECT AND READING THE CODE AND EXECUTE THE CODE 

I have designed a mobile controlling robot by using arduino programming . I have also made a stopwatch , fitness monitering system by using arduino. 

install arduino ide software and start programing arduino

see tutorials in youtube or arduino webside

At first we should know C progamming.

We should know of all hardware descriptions regarding arduino.

We should know inputs, outputs, power, grounding, synchronising etc.

We can learn about arduino development from in appropriate institute, internet, arduino facebook group etc.

The Arduino Software (IDE) allows you to write programs and upload them to your board. In the Arduino Software page you will find two options:1. If you have a reliable Internet connection, you should use the online IDE (Arduino Web Editor). It will allow you to save your sketches in the cloud, having them available from any device and backed up. You will always have the most up-to-date version of the IDE without the need to install updates or community generated libraries.2. If you would rather work offline, you should use the latest version of the desktop IDE.

Begin with Arduino is simple by exploring all the example programs with hardware components., for doubts arduino official website canbe used

Best way is using its official website or from instructable website.