The first thing you need to do is thoroughly wash the cilantro. I use some vinegar and water and soak the cilantro for a few minutes and then rinse it under cool running water to make sure all the dirt and residue is off the cilantro.
Once they are rinsed be sure to gently shake the bunch so most of the water is removed. Now lay the cilantro onto your dehydrator trays. I leave the stems ON but you can remove them if you prefer. I keep them on because most of the flavor comes from the stems.
Set your dehydrator to 110 degrees and let it run for 3-5 hours. They dry fairly quick but don't worry you can't exactly "overdry" them. They are considered "done" when the leaves are completely dry and kind of "crunch" when you pinch them.
Store the dried cilantro in an airtight container like a small canning jar. Store in a cool, dry place until ready to use. They should be used within a year. The flavor and aroma is intense so don't listen to the naysayers who say drying the cilantro loses its flavor. Just open up a jar that you have dried a few days after you store them and you will see what I mean.
I store my cilantro whole and do not crush or grind them down until right before I need them. This keeps the flavors intact.
Besides the ethnic dishes I mentioned earlier, cilantro can also be added to soups for a punch of flavor.