Squeak No More!
Before that door drives you stark, raving nuts, try the following quick fixes in the order below:
1. Squirt a little household penetrating oil or WD-40 on the hinges. Be careful not to spray the door or walls. Work that door back and forth a few times. Lubricate again and wipe up the mess.
Jane Tip: Hold a rag around the outside of the hinges to protect from overshoot.
2. Squirt a little dry lubricant, such as powdered graphite into the hinges. (Yes, it's the same sort of graphite found in pencils.) It's very slick and it can be messy. Work it back and forth until the door is quiet.
Jane Tip: When you're done with your hinges, squirt a little in your locks to keep them operating smoothly. You can find powdered graphite at most hardware stores wherever locks are sold.
3. Pull the pins out of the hinges to remove the door, and then lubricate the hinges from the inside out. The pin is the bolt that runs through the center of the hinge. Carefully pry it up from under its cap using a screwdriver blade. If the pins are stuck (which often happens if they've been painted over) you'll need to knock them loose from the bottom. Use a nail set and a hammer and gently tap them upward. Wiggle them out and pull the door off.
Put the doors on some newspaper to protect the floor. Spray the hinge and pins with WD-40, then clean and smooth them by rubbing with some fine steel wool. When you're done wipe them down, and then coat with penetrating oil (or, in a pinch use petroleum jelly). Reassemble the door and replace the pins (you'll want some help). Work it back and forth a few times.
4. The three tips above will cure 99% of squeaks. Part of the 1% club? Lucky you, you get to replace the hinges themselves (as if you needed an excuse to head for the hardware store.)
Buy a set of replacement hinges that are the exact same size and profile as the old ones (you did bring them along didn't you?) Replace the components and reassemble your door
Ah, peace and quiet at last.
Door Knob Know-How
How to Install a Deadbolt
How to Install a Peep-Hole