You can move layers in the Design view in much the same way that you move objects in most basic graphics applications.
If the Prevent Overlaps option is on, you will not be able to move a layer so that it overlaps another layer. (See Preventing layer overlaps.)
Hold down the Shift key while pressing an arrow key to move the layer by the current grid snapping increment. For information about setting the grid snapping increment, see Using a tracing image.