I know of a good web resource for a topic that other users will find helpful. How can I add it to QuizCenter?

On each topic page, below the resources for that topic, you will see the following text:
 
Do you know of a good resource for this topic?
 
Next to it you will find a button labeled "Add a Resource".  You should click on this button to tell us about your resource.  Please note that your resource will not become visible immediately to other users.  We will review your contribution before we include it on the site.  This process normally takes about a day.