Refer to "How to Create a New Item" before you start.

Creating a new folder is similar to creating a new page.

1. In the side bar on the left, select the folder within which you want to put a new folder.
2. Click New > Empty Folder in the top menu bar.
3. The New Folder screen will appear.                                                             
4. Click on the Perent Folder and browse for the department.
5. Provide a display name.No title is required for folders.
6. Tick Publish and Index until the site is complete. 
7. Click the Submit Button. The new folder will now appear in the sidebar and the folder information screen will be on the right.