My first experience with photo editing software was Photoshop Elements. A friend has it and even after some courses, still hasn't mastered it (but that's partly his fault too).
Then I downloaded GIMP (GNU Image Manipulation Program). It can do more than PS Elements, but not as much as the more advanced versions of PS. I know people who have switched from Elements to GIMP.
I also discovered a site called "Meet the Gimp". For almost 3 years, this site has offered a weekly video tutorial about how to improve images using GIMP. And there are other tutorial sites.
The best thing is the price: BZ$0.00 (US$0.00). The program is a free download, and the tutorials are free. GIMP is open source software for Linux, but there are versions for Windows & Mac.
Here are the relevant sites:
Current stable version is GIMP 2.6.7http://www.gimp.org/http://meetthegimp.org/http://www.gimp.org/tutorials/http://www.gimpusers.com/news/2009-02-28/exceptional-plugin-photo-restore.html