Ruler guides are different from grids in that they can be positioned freely on a page or on a Drawboard. You can create two kinds of ruler guides: page guides, which appear only on the page on which you create them, or spread guides, which span all pages and the Drawboards of a multiple-page spread. The guides can be placed horizontally and vertically.
Note: Make sure that guides are visible on the Drawboard, for doing that hover the cursor over the Preferences button and switch on the Show Guides option.
For creating a page guide position the pointer inside a horizontal or vertical ruler and then drag to the desired location on the target spread. If you drop the guide onto the Drawboard, it spans the Drawboard and spread; it will act as a page guide if you later drag it onto a page.
For creating a spread guide, drag from the horizontal or vertical ruler, keeping the pointer in the Drawboard but positioning the guide at the desired location on the target spread.
You may also change the position of your guide by typing the position or just drag and drop.
Note: If you want to have a Drawboard guide on your page keep pressing Control while you are dragging the guide.
For deleting the guides just select them by clicking or dragging over them and press Delete.