Unless they have had some experience of image editors at some point, many people will simply shy away from use them. Many of the more expensive and professional-level applications are far too comprehensive for most and many of the features that ship with them will never be used by most novices.
If all you require is a tool to touch up photographs or merge images, FotoMix is worth a try.
The application is free and ships with a simple, user-friendly interface. You can use the editing features to add, remove and combine elements, as well as edit photographs using the application's simple five-step editing process.
Note that the application includes advertising.