The Gimp is a superb piece of software! It is so powerful that you can do pretty much anything you can think of with this beauty. That comes at a cost though. It's not the most intuitive piece of software on the market. But at a grand total of £0 !!! it's worth getting to grips with. 

The Gimp is recognised as one of the greatest pieces of Open Source software available on the internet today, and is available for every computer platform (Windows, Unix, Linux, Mac OS, to name but a few). 

At the very least you can download it and see how you get on before spending money on something else. For most peope it is comparable with the best of the best, namely Photoshop.