Adding a link to a unit using the Link assignment type gives your students quick access to a webpage outside of LaunchPad. If you need to provide a text description with your link, consider using the HTML Page assignment type. If the link is part of an assignment with a grade, you can use Offline Assignment.
Open unit and add to it
From your home page, open the unit to which you want to add a link and click Add to this Unit.
Add title and URL
Under the Basic Info tab, choose a title and paste the URL (in this case, http://www.scientificamerican.com/) into the box labeled URL. When you are done, click Save.
Go to the Assignment tab. Choose a due date, point value, category, calculation type, etc. When you are done, click Assign.
Click "Done Editing"
When you are finished making changes to the assignment, click Done Editing at the top of the page. You will be brought to the page for the link you added (in this case, Scientific American).