Begin by clicking on the "Course Admin" tab in the blue nav bar and then clicking on the "assignments" tool. Edit an assignment by clicking on the caret next to it, or click on "New Assignment." From the assignment editing screen click on the "Attach Link to Existing Activity" icon.

From here choose the type of content you'd like to link to.

Then click on the individual piece of content you'd like to link to.

The link will appear as an attachment at the bottom of the page.

Click on the blue "Save and Close" button. Now students will see the linked content as an attachment below the assignment instructions.