You can select which page to work on using these icons. Anything you place here can be copied to any other page easily, appearing as a default element. Select the Master Page now by clicking the Master Page icon. We are going to set up the guides and graphic elements that we'd like to appear on every common page. To create a guide, simply click on either the horizontal or vertical rulers on the document window and drag a guide to the correct place on the page.
Guides usually appear a light cyan blue.
You can move these guides after they are dropped if you wish. Now, we will use these guides to set up our graphic elements. Choose the Square tool from the Tools palette. Create a square by clicking where you'd like the top left corner to be, and dragging the square to the desired size. You can hold down the Shift key to constrain the proportions and make sure the square remains square.