The bad news is that a leaky, dripping faucet wastes water and the sound can drive you crazy. The good news is that a leaky faucet is one of the simplest repair jobs you can do yourself.
The most common culprit is a corroded valve seat, tired gasket, or worn o-ring. And the most common mistake homeowners make in repairing or replacing these parts is to try and use one that won't match your system. So be sure to lay out all the parts when you dissemble your faucet, identify the ones you need or, better yet, take them along to the hardware store or home improvement shop.
You should first identify the kind of system you have. Compression faucets are the common variety that require washers. In your considering bathroom or kitchen faucet repair, check to see if you have a compression setup or one of the three other common "washer-less" systems.
Now you'll need to determine which replacement parts you'll need for fixing your faucet. The writers at DoItYourself.com identify critical replacement parts as faucet stems, o-rings and gaskets, and the Bibb screws that hold your washers in place. A commonly dismissed piece of the puzzle is the plumber's putty or tape to seal the threads as you reassemble your faucet. So stock up.
If you're the proud owner of a "washer-less" system, you'll have to find another cause for your woes. The best solution, according to the writers at H2ouse.org, is to take the entire faucet assembly to the hardware store. If there's nothing wrong with the faucet itself, and you're still seeing unreasonable water bills, then you may have a leak elsewhere in the plumbing.
Getting Down to the Repairs (Note: Cover your sink with a thick towel before you begin to protect the basin from any parts or tools you may drop into it.)
First, you'll need to remove your facuet handle by removing the decorative cover with a screwdriver to reveal the actual attachment screw. There is a packing nut that you can probably remove with a wrench or pliers. But be careful not to bend or scar the metal by using excessive force. The spindle or stem assembly will rotate out from the housing in the same direction you'd spin it if you were turning on the tap.
Common mistakes in doing your own kitchen faucet repairs can occur when you work impatiently, forget to turn off your water supply, use old parts that really need replacements, or strip the threads.