The drum brake part, the parking brake should be visible with the rotor off. The rotor is actually a rotor and a drum in one. If you look at the pic here
http://partimages2.genpt.com/partimages/667714.jpg you can kind of see how big the rotor is. The drum is the upper part in the pic. The shoe is a one piece shoe that fits inside the drum. It looks almost like an omega symbol or sort of like a horseshoe. But, if the wheels spin free with the service brake removed it is probably more likely service brake related. Sticky slides or pistons are the likely culprits.