What sort of software & hardware do I need to use shaders?
How to do the shader?
How to link shader to the program I am writing?
What in the fact is shader?

Please, aswer me these questions or give the links that can be useful. Thanks.

First youll need a graphics card that supports opengl 1.5 or directx9. As for how the shaders work and get them setup i might recommend the new orange book !