There's a very powerful free imaging program called GIMP. (It's short for Gnu Image Manipulation Program. stargatefangurl and cha_aka both make really awesome graphics with it. It's a little tricky to learn how to use, but once you get the hang of it, it's a good program. There's also GIMPShop, which is basically a modification of GIMP's program code that makes the interface a bit easier for some people to use as its designed to have an interface that looks a lot like Photoshop. I use Paint Shop Pro 8, which costs about 1/6 of Photoshop. The program has a free trial and total cost is about $100 for the latest version. So there are alternatives.
Re: Very good!
GIMP (http://www.gimp.org/)
PSP (http://www.corel.com/servlet/Satellite/us/en/Product/1184951547051)