Brakes making a noise when pressing pedal, or e-brake one click?

My car has been making a noise in the rear when I step on the brake for awhile. I finally got around to taking the drum off today and cleaned up the rust ridge around where the shoes touch, and where the drum tucks in under the dust plate - which didn't help it. How can I cure this annoying noise? The car is an 08 so nothing is really corroded much anyways, and it's only when pressing on the brake. The shoes look fine and cleaned everything spotless. Any ideas?