If you have a copy or snapshot of a working operating system already installed in a qcow2 image format, you can upload them directly to the Cloud.
Navigate to: Templates -> Select View -> Templates. Choose Register Template.
In the next screen, enter all the requested information about the Template. A valid URL should be where the qcow2 image can be retrieved. If you make the Template "public" you allow other users of the cloud to use the template.
Note: A template can only be made based on a qcow2 image.