My Trail 2's rear brake rubs and makes a shh-shh sound with every wheel turn after I've removed the wheel. How do I fix it?

Make sure the wheel is fully seated in the frame. Loosen the two caliper bolts slightly, squeeze and hold the brake lever, then retighten the bolts so the caliper centers itself. Release the lever and spin the wheel. A tiny remaining tick may be a slightly bent rotor, which usually wears in.