I've done lots of dehydrating in the past; I have about 5 or 6 of the dehydrators, picked up at various garage sales. If your family loves fruit leathers, that's the easiest thing of all to make. Take your favorite jar of applesauce and just pour into the plastic tray that sits on the other trays (usually one comes with each set). If you want other leathers, just puree any combinations. Drying times depends on humidity. I've dried venison jerky, bananas are fast and delicious (just slice, don't make too thick or thin) with no preservatives, apples are peeled and cored then sliced. I add them into large containers of oatmeal with cinnamon and ground flax meal for fast breakfasts.
One thing I find that helps is spraying Pam on the trays before putting the food on them - otherwise it's tough to pry up sometimes.
Oh, one VERY important thing not to dehydrate - Mushrooms! You cannot imagine how horrible the smell will be. And it takes forever with that disgusting smell in the house.