If you are new to Arduino, or need some further detail on how to install the software and where to save Sketches, you can find detailed instructions for windows here :
Download the Sketches and Library here :
Extract the zipfile and move the " BasicLineFollower_08232015a" and “MotorDirTest_08232015a” folders to your Arduino sketches folder.
Move the "QTRSensors" folder to the Arduino libraries folder.
Plug in your Arduino/Redboard to your computer with the USB cable.
Open and upload the “MotorDirTest_08232015a” sketch.
Open the Serial Monitor and test your motors for correct wiring. See comments at the top of the sketch to help you make wiring changes if needed.
After the motors are turning correctly, open and upload the " BasicLineFollower_08232015a" sketch.