Once you have a photo of your image saved to your computer, simply open Photoshop & Open the file by going to FILE > OPEN
& browsing to the location of your image on your hard drive.
Once it is opened in PS, go up to LAYER > NEW > LAYER
. This will add a new transparent image to the layer which you can view on your layer palete.Note: It helps if you rename your layers. You can change the name of the layer by double left clicking on the text (example: where it says "Layer 1" or "Layer 2" in the above screen shot) so that you are able to better identify which layer is which. (Example: Layer 1 is the layer my image is on, I could name it "background" or "image" and then I know not to add new elements to that layer.