Creating a Teaching File is as simple as 1,2,3.

Step 1:  Log on to your institution portal.
Step 2:  Create your cases using the Teaching File (TF) Editor from the create case link on the menu bar.
Step 3:  Make the cases view-able to your residents by setting the cases to "Portal" visibility.

Your residents can now view the cases under the sub-specialty icons from your institution portal!

Helpful links:

The Institution Portal - Gateway to Cortex

Creating or editing cases using the Teaching File Editor

Image Annotation using Teaching File (TF) Editor

Questions and Question Types

Portal Visibility or the "Only Me / Portal" Case Configuration