Gimp
Gimp is a free program that can be downloaded from the internet for your use. If i had to put gimp in a family, I'd make it a cousin to Photoshop.Lots of the things you can do in Gimp are very similar to what you can do in photoshop. If you cant get your hands on a copy of photoshop i think gimp would be the next best thing.
It not only can do similar things to photoshop but lots of photoshop brushes can be changed to work with gimp. :D Drawing, making cool Layouts, making your own brushes, and adding cool effects to images are only a few of the awesome things you can do with gimp. If you don't already have it, get it!