The brakes squeaks a lot and I jacked up the car and decided to change the brake pads. However, when I took off the tires I noticed that there was a lot left on the pads. The rotors looks really good too, but how do I fix this problem? Also, sometimes it sounds like it is grinding the rotors.

Oh, it's not brake dust.

 

it may require grease on the backing plate...

 

Yeah, try pulling the pads out, putting some 'brake quiet' grease that can stand hot temp on the shims. You do have shims on your pads I hope!

 

I completely forgot about using the grease to get rid of my problem. The great news is that I don't have anymore problems.
Thanks.