Here's the way in ePub Maker.
1 Do not include any cover or cover image in Word manuscript.
2 After import, click Cover tab and load the cover image.
3 ePub Maker will automatically generate a cover page for ADE,
also arrange this image as cover for iPad.
You can reference any example on
http://epingsoft.com/epub/examples.asp
or click "Open Example" in ePub Maker.