Gimp for me is a complicated graphics program like Photoshop but I do have it on my Linuxes.
If I wanna edit or even draw pictures, I only use 2 programs. One is MS Paint in Windows 7 because even if its abilities are limited, it does the job for me- resize, crop or even change and modify things in the pictures.
Another one use I Photo! Editor. Its not s perfect program though as it would bug up from time to time so I had with me its installer to do reinstalls in case it fails. But disregarding this bug, it works well. It has cropping, resizing, color enhancement, blur, sharpen, makeup and caricaturing abilities, so its not all bad. It has a tabbed interface so its so much more easier for me to use.
Photo! Editor - The perfect choice to edit and improve your photos
The combination of these two programs allowed me to make some good artworks, though I'm no professional but at least, its something I can show.