Shoes are only for rear drums and it sounds like you have disks, (with pads) right? The face of the rotor should be clean steel with some very mild concentric grooves. If your disk surfaces are rusty or uneven, the pads and rotors will need to be replaced and you may have caliper problems because your pads may not contacting the disks.
The rear pads are easy to inspect and replace. Just remove the wheel, pull the pin out of the caliper and it will pivot open to allow the pads to be removed and checked out. Turning or replacing the rotors is generally done when ever the pads are replaced.
