If the dryer is brand new it should have a hand book with the details 
 Dummies guide to preserving & canning  has a bit of info .
If I recall correctly there is a JeBoufe ( sp ) dehydrating book as well , it can be FOC for Kindle PC laptop etc. or printing off ..
 If you look up some USA websites for" safely dehydrating  food + USA "  you can find their national guidelines from  most of their university extension departments on line , you can down load & print these as well for free