Fold a piece of paper into thirds to determine your brochure layout. Fold it into a "Z" shape, or letter style by folding one end up toward the center, then the other down toward the center, over the first flap. Number the sections of paper to determine which panel will correspond to each page of the brochure.
Open Microsoft Word, Open Office, or your favorite other document-creation program. Click "File" and then "Page Setup." In Open Office, click "Format" and then "Page." Select "Landscape" from the "Portrait" or "Landscape" options.
Click the "Columns" tab under the page format section and select "three." If using Open Office, check the "Auto width" box.
Type your desired text into each column, using your folded paper as a layout reference. Continue onto a second three-column page for the back side of your brochure paper, again referencing the folded paper for column order.
Print a test page once you have one page of three columns complete. Adjust margins and layout as desired.