When you go to insert your image, a pop-up window appears called Image Properties. Once you've filled in the URL of your image, either by browsing or by linking, the Width and Height fields are automatically set to 0. You image does not appear in the Preview.
If you click the purple Reset Size arrow to the right of these fields, your image's original width and height will be restored.
Unfortunately, until this issue is resolved, you will not be able to utilize the image resizing tools built into the School of Medicine Web System. However, Photoshop actually does a much better job resizing images. This software is available free for use by School of Medicine faculty and staff at the Faculty Multimedia Lab.