@1Dlover325 Well....you have to find a picture for your cover first. You want to make sure that the picture isn't copyrighted so it's easier to just take your own pictures for it. and Then you just use a simple photo editor....Picasa, Gimp, or Google+ are the ones that I tend to use but any photo editor works. Just make the picture look the way you want it and add in the title and you have your book cover :}
There's a club for Book Covers if you look under the clubs in the Community Section. In there pinned at the top of the discussions you can find a how to discussion if you want more indepth details :} It has pictures too!