Arduino first steps
Step 1: Attach the Arduino to your computer
Using an USB cable, attach the Arduino (Arduino Nano or Arduino Mega) to your computer as shown below.
Step 2: Download and install the Arduino software
Click here to download the Arduino development software to your computer (Windows users should download the 'Installer' version on that page):
http://arduino.cc/en/Main/Software#toc3
Install After the download completed, install the Arduino development software on your computer:
For Windows, double click the file 'arduino-1.5.8-windows.exe' in your Windows file explorer.
Step 3: Run the Arduino development software on your computer
After the installation completed, run the Arduino development software by double clicking the 'Arduino' symbol on your Windows desktop.