Ok, if you're just making a quick page then don't merge any layers at first. Cut out the space where the photo will go on all the layers below where you want the picture. Making sure you have each layer selected that you are deleting the space on. Then you need to save it as a png file at full size to let the hole show so people can add their pictures. Then you can save it at 600x600 as a jpg to put in the gallery. You don't have to merge the layers yourself as when you save it the layers will merge themselves. I hope that is half way understandable. I can make things clear as mud sometimes.