Been using GIMP for ages and unless our in need for a specific PS exclusive tool/filter GIMP is more then enough for all image editing needs.
That said if your new to image editing or looking for a more user friendly interface you should really check out Paint.Net which is still a powerful editor.
One thing I love about Paint.Net is its extremely extensive yet friendly online tutorial+plenty of video tutorials on the web, I'd start there and see if it meets all your needs ;-)

Note that the newest major version of Paint.Net, 4, will require installation of .Net Framework 4.0.
I like how Rick always pushes for the latest technology.