You must create a module before you can add topics. You can also create sub-modules (modules within existing modules) to establish a deeper hierarchy.

Create a New Module

From your course homepage, click Content from the Course Materials drop-down menu.

screenshot step1

Click the Table of Contents link in the left hand panel.
Enter your new module title in the Add a module... field and press Enter.

screenshot step2

Create a New Sub-Module

Click on the module you would like to add a sub-module to from the Table of Contents panel.
Enter your new sub-module title in the Add a sub-module... field and press Enter.

screenshot step3