Car Won't Start? Loud Clicking Sound? Always Check this first!

Car Won't Start? Loud Clicking Sound? Always Check this first!
Clicking sound and the inability to start can usually be caused by low power being supplied to your car's starter motor. 
Open up the car hood and check the car battery. 
If you see, crusty sometimes white, yellow, blue, green deposits on the terminals, clean the terminals to restore proper voltage supply from the car battery. 

Battery 
Check the battery connections for corrosion and or looseness.
Clean the battery terminals and tighten the connections.
Check the Battery Voltage. The battery should be over 12 volts.
If not, charge the battery. 
Or use battery jumper cables to jumpstart the car.
If the battery is charged and battery voltage is sufficient, the problem may be in the starter.