Once students have taken photos and loaded them into the computer, they'll be ready to use a photo editing program to jazz up their shots. I recommend using one of these easy-to-use products:
Adobe's Photoshop Elements is a perfect starter package for students in grades 3 and up. Several correction tools are available, such as remove red eye and crop, along with templates for projects.
Image Blender from Tech4Learning is another great program for students. In addition to the standard editing tools and templates, it includes the ability to create slide shows.KidPix is excellent for working on projects with younger students. It can open files in .jpg format (the standard for most digital cameras) and is a tool that your students are probably already familiar with.