Have you ever tried to set a single Ruler Guide across a two-page spread in InDesign– and been frustrated in the effort? A Ruler Guide that extends across a spread is called a Spread Guide. To create one, set the view so you can see the Pasteboard and then drag the guide out across the pasteboard instead of across the printable area. Viola–it extends all the way across the spread. If you are zoomed in, hold the Ctrl key while you drag.
To place a copy of a Ruler Guide or Spread Guide on other pages, point to the guide and right-click when you see the cursor change. In the right-click menu, choose Copy. On following pages, from the Menu bar, choose Edit, and Paste in Place.
Remember also that you can only see Ruler and Spread Guides in Normal view.