In any of the tabs in an object (in the default shader, inside parts shader, inside object, inside population - if used in a pop) you can import an image map, so you'd need to import one in color, one in displacement (usually a greyscale bumpmap) and one in opacity tab. If there's an alpha channel in the texture map, import the same color map in opacity tab and check 'use alpha'. That's simply the basics.
If you want them, and other shaders you add inside the object, to stick, save the object as tgo for future imports. All shaders will be there.