I'm always editing images and creating graphics on the web. The good version of Photoshop is super expensive. So, I learned how to use Gimp. I'm not a professional designer. So, anything I'd want to do is covered using this program. It's free and easy to use.
A simple tutorial created by Gimp. It explains the basics of how to use the program. Another long read, but probably worthwhile.Edit Remove Move
The full list of tutorials provided by Gimp.Edit Remove Move
Basically, this is the open-source, free version of Photoshop. If you go to the homepage, it doesn't look like much. But, it's pretty powerful and will take care of any image editing/creation that you need - I promise.Edit Remove Move
A very basic introduction to the simple features of Gimp 2.8.Edit Remove Move
This is a really long read. And, it's not designed that well. But, it answers any questions that you'd have about Gimp. it's the complete documentation.Edit Remove Move
Pretty simple tutorial. Removing a background might be the most important thing you could learn with image-editing. Just remember to save it as a .png :-)Edit Remove Move
Gimp beginners guide. Explains most things you'll need with Gimp.Edit Remove Move