Generally your front brakes provide 80% of your stopping power, so they tend to wear away more easily than your back brakes. But that doesn't mean your rear brakes don't suffer wear and tear as well.
If your back brakes have been making squeling or squeaking sounds, then you'll need to replace your brake pads. But if your brakes have been shaking, then you'll have to completely replace your rotors.
This video shows you all the tools you will need and how to do the job.