When you load this page, over on the right hand side you should see some sidebars. Most people have Breaking News, FrontPage, Extended, Editorial, FR, and Announcements.
The table above shows all the different topics you could have as a sidebar. If you click the link in the first column, you get a page that shows you what is currently in that topic. If you click the link in the second column, it adds that topic as a sidebar for you. And if you click the third column, if you had it as a sidebar it removes it.
If there is anything that you don't understand, I will be glad to explain better, but you will have to tell me more about what is confusing you than just "I don't get it". Get what? Or more than "I don't get how to make it work." What work? What is it you are trying to do that you can't get to work? Thanks, AM