This tutorial will show you how to make a decal, and add it to your surface of part. This will also be visible in renderings.
First start by clicking on photoview 360, and clicking on Edit Decal.
Browse for the picture that you want to place on the surface of your part.
If the background of image is one solid color, you can make it transparent by clicking "Selective Color mask," and taking the eye dropper to the color you want GONE.
Find the Decal you made, and drag it onto the surface of your part.