Using Gyro to turn robot during Autonomous

[chriz4gx]

So this year my team is trying to use a gyro to make the robot turn exactly 90 degrees during autonomous. How would I make the gyro turn the motors of the drive train to successfully turn the robot 90 degrees? How would you wire the gyroscope, since its my first time using gyroscopes? How would the placement of the gyro in the physical robot effect what 90 degrees actually is? If you have any tutorials or examples that do such a thing please direct me to them. Thanks in advance