Now we need to create the column guides, since this brochure has three equals columns creating three content areas. There are several ways to add those guides, one of them is to grab the calculator and divide the width of the paper by three (11 / 3 = 3,6666), kinda hard right? One of my favorite tricks to create several columns with the same width in both web and print design is to use some temporal shapes.
Start drawing a Rectangle (U), use the guides, start on top-left on the corner of the "Main area" guides intersection, and drag the rectangle until you reach the bottom "Main area" guide.
The width of this temporal shape isn’t important, just try to make it a little narrow. Then, change the tool to the Move Tool (V) and select the first rectangle, ensure the Show Transform Controls option in the Options Panel is checked and then duplicate the rectangle; you can do it by Alt-clicking while you drag the selected vector shape.
Place the copy just next to the previous rectangle with first rectangle’s right side touching the second rectangle’s left side. It’s really easy actually. I’m changing the color of the copy for graphic purposes (See the image below).
Duplicate a third rectangle and place it next the second one, as shown. Once you have the three rectangles ready, ensure there’s no space between and there’s no overlapping. Select the three rectangles, then in the Layers Palette (Hold the Shift key and click on every layer miniature) Go to the middle right Transform Control and expand the three rectangles until reach the right "Main area" guide.
This transform process will expand every rectangle in the same proportion. Next, just select the middle rectangle using the Move Tool and use the transform bounds as a limit for two new Guides for the columns. Finally, delete the rectangles