Making eCovers for digital product. TBS Cover Editor2

Does anyone have experience at designing an ecover? I learned of TBS Cover Editor2 on this forum and have designed a cover for me ebook, but now I'm kind of stuck? Here's a post I just made on their forum, but thought I would see if any of you have insight also.

I've made a nice design for an ebook, using Cover Editor 2. Now I have a cool animated gif that I can use on my website. But a couple questions remain.

When I have saved my designs by exporting, then I get multiple 2D images Front, Back, Spine in the form of jpg, bmp, etc. I intend to put my ebook on Amazon Kindle, Goolge Books, etc., and I am still not at all sure how to take what I've designed and:

a) attach it to the pdf (if this is possible), so that the file has the look of the book and

b) I don't know how to take these 2D images and have it end up looking like what i've designed in the software.

The software made this .drc file, but i'm not sure if i will convert that or what? How do I get from having this design in the software to i.e. having something I can show on Google Books?

I agree that some more video tutorials would be very useful! Having said that, can you give me some guidance on these points above?

Thanks!