Acquire the images you would need for the book cover either with the help of the camera or by scanning whatever pictures you feel would represent your story best. You could choose more than one picture or photograph to make a composite that would represent different chapters in your book.
Transfer the pictures and photographs to the computer and ensure that you save all of these pictures in a folder on the desktop for easy access. Use software such as Photoshop to organize the image(s) into a beautiful palette that transmits your idea about the book to the prospective reader. With Photoshop, you can also add graphics to your photographs and spruce them up a little.
Save the file carefully and then print it on an ordinary paper to find out how it look. Look carefully at the colors, size, mix of the subject and the overall picture.
Cut the paper to the size of your book and have it stapled or fixed in any way you find convenient.
Print the final product on your glossy paper and enjoy your new glossy book cover.