The Association football Portal was created via instructions in creating a box portal. Clicking the edit button on the main Association football Portal page does not help at all to add to the various sections as is usually the case with creation of Wikipedia articles. However, clicking on the edit button does show all the pages transcluded into the main Portal page.
This page gives basic instructions and further reading links for adding new content to the portal. For more in-depth information into how the Portal was created, how the various templates work, what the layout wikimarkup does and how to make new pages or boxes see the instructions for advanced users.