If you search Google for "Free Ebook creator" or "Free Ebook Software" you will get tons of results and pieces of software that will help you make the perfect e-book cover .
Try this one:
101 FREE Ebook Covers is an eBook in PDF format that has 101 professional eBook Covers. These images are .jpg graphics and can be used in many graphic editing software programs, so you shouldn't have to learn a NEW graphic editing program! These covers are also designed at a SLANT so they are more commonly accepted as 3D eBook Covers. Throw away your 2D Covers and use one of these to create a more perfect look to your eBook Cover!