The workspace is designed for desk productivity, so it is densely packed. If you're using anything less than a 24 inch screen, you'll have problem fitting the preview.
IMPORT LIST contains content from your Content Sources (usually article databases). Drag or press '+'-button to add content to EDITION LIST.
Click an item in your EDITION LIST and the form for that item will open in the EDIT ITEM FORM-column.
Whenever you add content to EDITION LIST or make changes to EDIT ITEM FORM you'll be able to see a live preview in the far right column.
To optimise space, use the small sideways arrow "<" located bottom left. This frees up space. You may also grab the corners of a column and resize to fit
If you are on a too small screen, or if you have a secondary screen, you should consider closing the preview, and pop it out into another window. Close it by clicking this icon above the preview
Then press the preview button to pop out the preview into another browser tab. The preview is still connected to your editing in real time, so you won't miss any features.
You can even move the preview to a mobile/tablet (any browser device) by copy-pasting the link from the preview browser tab. It'll still work the same way.
If you're still pressed for screen space, use the small button on top of the DrEdition GUI to show/hide the IMPORT LIST. Use this button: