Thanks to a deal worked out by Kent State's Division of Information Technology, Kent State students now have access to a heavily discounted subscription to Adobe Creative Cloud. For just $75 per year, students can download any or all of the products offered through Adobe Creative Cloud - from Photoshop to Lightroom, InDesign, Illustrator, Premiere Pro and more. For more information, visit software.kent.edu.
A free alternative to Photoshop. You can also find documentation and tutorials on this site. It looks like it has most, if not all of the features of Photoshop but Photoshop users might find the interface a little hard to use at first. A novice, though, might find it to be just fine since they don't know any better.
(Windows only) A cross between MS Paint and Photoshop, Paint.NET is a free image and photo editing software. It features an intuitive and innovative user interface with support for layers, unlimited undo, special effects and a wide variety of useful and powerful tools. An active and growing online community provides friendly help, tutorials and plugins that add many more Photoshop-like features.