GIMP
Cost: Free
Category: Photo Editing Software
GIMP is a popular open-source image editor which was originally developed for Unix/Linux operating systems. Many photographers consider Gimp to be the free version of Photoshop. Gimp has an interface and features similar to Photoshop, and also a steep learning curve to match like Photoshop. Where is falls behind Photo shop is its support, stability and frequency of updates, but many photographers are happy users and report that GIMP works similar to most pro photo editing software products.
Gimp is one of the most advanced free photography software available. It does almost everything that Adobe Photoshop does and it is completely free. There’s even a version that mimics the look of Photoshop so you can get used to it without having a steep learning curve if you have transferred across from Photo shop.
GIMP tutorial "Basics"
GIMP tutorials for beginners – Shiny Glossy Button
How to use Gimp for beginners – Lesson 1 – Getting around GIMP
How to use Gimp for beginners – LessonTwo – Under the Hood
How to use Gimp for beginners – Lesson 3 – Layers and Selections
GIMP Lesson 6 Part 1 – Working with Layers Part 1