@rhban - Krittika has some instructions mentioned in her blog post here which may be of interest:
There have been quite a number of ways to customise the covers added over time which is why perhaps all the options might seem intimidating at first. If you still can't work it out, crank up your favourite paint program and attach a screenshot of the layout that you want and one of us can tell you what settings you need to set for it. For instance are any of the layouts you see on the screenshots in my first post of this thread along the lines of what you want? (Forget the image itself as that is easily adjusted - just the basic layout of where you want the title text, authors and image placed, either as a background or inset on the cover).