Some links.... https://www.youtube.com/user/GIMPtricks This is for the home page on YouTube for Gimp Tricks, these are really easy to follow. I would watch them all, starting with the beginner/basic ones just to get a nice feel for what is where. These are older, so the newest gimp might be slightly different, but still the basics are the same. This is for see through text, which makes a really nice watermark. Other than this, you can make anything a watermark just by lowering the opacity on the text or graphic.