Ever see those little coordinate buttons in your Texture Input panel beneath the mapping methods such as Orco, UV, Sticky, etc. and wonder to yourself - what are the XYZ coordinates for my geometry? This small article describes exactly what is going on with those buttons and how you can use them.
The article explains how to figure out the axis geometry of your model and then goes on to explain how those 9 confusing buttons are used to map textures to your object. One of the key tips mentioned in this article is:
Sometimes figuring out how to map an image onto an object can be dizzying. It gets much easier once you get a look at your objects axis!
Read the the article here.