The easiest and quickest method of dehydrating food is to use a dehydrator.
The most energy efficient way is to sun or air dry. Air or sun drying works best if you live in a dry climate with lots of hot days.
I don't have any experience drying items in the oven. It seems to me that it would be very inefficient. If that is all you have and you are just dehydrating food in small amounts it does work.
For a complete listing of my Dehydrating Food Articles.
The more evenly you can make your slices of food, the more evenly the food will dehydrate. These are my favorite tools to use.
A mandolin slicer(on top), an egg slicer (to the right) and a gadget I picked up somewhere and don't even know what it is called! (to the left) I call it my tomato slicer because that is what it works best for. The egg slicer works for soft items like strawberries but not too much else. The wires will bend if your food is too strong. The mandolin is best for firmer items like zucchini or sweet potatoes.
A good knife. (I didn't take a picture, surely you know what a knife is right?)
The most recommended dehydrator on the market is the Excalibur
I personally have a commercial dehydrator from Cabelas
Other popular Dehydrators... is yours listed here? Tell us what you think. Help others know what to get or .... NOT get.