If you see coffee rings and residue on your coffee carafe, or pot, imagine what the inside of your coffee maker looks like! Clean the carafe and the internal parts of the coffee maker. You'll be surprised at how good your coffee tastes when it's made from a newly-cleaned machine.
Pour white vinegar into the coffee maker reservoir, where you normally pour the water.
Leave out the filter, unless your coffee maker has a reusable metal mesh filter. Keeping the mesh filter in during this process will get it clean of residue and stains also.
Run the coffee maker through a normal cycle. When it's done, let the vinegar sit in the carafe for 5 minutes. The strong smell of vinegar will disperse quickly, but open the windows if it bothers you.
Dump the vinegar out and fill the reservoir with clean water.
Run the machine through another cycle. This will rinse the vinegar from the interior components of the coffee maker.
Finally, wash the coffee pot, mesh filter and other removable parts with soap and water.