Adding sidebar content on one or more pages requires you to create a block and place that block on the page where you want that content to appear. Choose this method if you have common sidebar content that you wish to appear on many pages or a few pages, or if you only have a few pages that require unique content in their individual sidebars.

First, create your new block:

1. Structure > Blocks > + Add Block
2. Do not give your new block a title unless you want that to appear at the top of your block.
3. Do give it a description such as "About Page right sidebar content" or something that is meaningful to you.
4. Add your sidebar content now or place some dummy content for now.
5. Scroll to the bottom and indicate if you want this block to appear on all pages, some pages, or only one.
6. Save by selecting "Save Block."

Now you can place your block in your site:

1. Structure > Blocks
2. Scroll to the bottom to see the disabled blocks and locate the new block you just created. By default, the block will be in this area.
3. Move your block into the page section in which it should display: either grab the cross icon to the block”s left and drag the cross up into the appropriate section, or:
4. Under the Region column, select from the drop-down menu the appropriate section in which your block should appear.
5. “Sidebar first“ and “Sidebar second” are the Drupal names for the left and right sidebars, respectively.
6. Save by selecting "Save Block."