Custom Dashboard Widgets

Does anyone know how I can achieve custom dashboard widgets? I am setting up a custom post type on a single site. I have many custom fields but I want to replace the large content box with in instruction box. I would also like to add a widget to upload a photo in the sidebar of the dashboard that will appear as a custom field. Here is a screenshot of another site that already has this done (I don't know them, so I can't ask how they did it.) -->