Yea, put the bones in a ziplock bag and they should keep for a few months in the freezer until you need them. As for animal fat, get yourself a set of Pyrex ramekin bowls and save a few glass salsa jars. You pour the grease into the ramekin, let it cool briefly, and then pour the grease into the cleaned out salsa jar to store in your fridge. If you bake on a regular basis, just warm up the grease and use it instead of vegetable oil or shortening to the same amount. It really adds to the taste and smell, to say nothing of the money you save.