Lots of people think using a layer mask is only for the advanced Gimp users, fortunately this isn't the case at all. Let me explain you the basic usage of layer mask on a easy to follow step-by-step example.
You can upload and import any MS Word document file to Google docs/drive as you can download and export a Google docs document to you computer and open it with MS Word.
You will learn how to manipulate a photograph in a way it will look like an object, melting snowman in my case, is sticking out of a photo using Photoshop CS5.
If you want you can turn any Microsoft PowerPoint presentation into a video so you can play the presentation on a computer that doesn't have Microsoft Office installed.