Well, there are many many ways you can make art on your PC! Photoshop is good for most 2d art and to make textures. 3D art can be made with many 3d graphic packages that are around.

You can use these programs that are FREEWARE!

THE GIMP --> [link] Is a lot like Photoshop and you can make some good 2d art with it!

ART RAGE 2 --> [link] Is like painting with paint on your PC and it is pretty easy to use. (YOU CAN GET THE FREE VERSION)

Wings3D --> [link] Is a FREE 3D Modeling Program. I still use it for most of my 3d Models. Vrey cool if you ask me!!

Blender 3D --> [link] Is a FREE 3D modeling program. It has many more features then wings3d. Including better rendering and the ability to make animations. It is pretty hard to get used to the interface though..

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Of course not all software is free.

I think PHOTOSHOP is a MUST HAVE for 2d art on the pc. It is good for everything really! --> [link]

Corel Draw is a good one also --> [link]

Lightwave 3d is an excellent 3d modeling/rendering/animation package. --> [link] I use it.
THere are many other 3d apps also like -- 3dsmax, maya and cinema4d. You may want to look those up as well.

There are some really cheap and easy 3d apps also that are pretty easy to use. Like Bryce 5.5 and Poser.

I like to use Vue 5 Infinite myself but it is not as cheap --> [link]

Well, maybe this will help you out.. GOOD LUCK!!