Creating, editing, sorting, and deleting items works just like the other story components.
Items allow you to track things that are important to your story. For example, the ring in Lord of the Rings. MacGuffins. You can use items for anything, really. Additionally, like characters and settings, items can be attached to scenes so it's easy to know where the item is (or is talked about) at all times.
With the basic Hiveword plan, items are quite generic. While this is enough for many purposes, you might wish to track things in more detail. For example, types of starships or magic spells along with very specific fields to describe them. If that's the case, custom types and fields in Hiveword Plus is the solution.
Moving/Copying to Another Story
Whether you want to move or copy, the way to do it is to select "Move/copy to another story" from the Actions dropdown menu on the the screen for the item you want to move. You'll then be given the choice of where to move or copy it.