For any old face or object, you select the object(s) you wish to texture, create a material (blinn, lambert, phong, whatever) and beside the "color" attribute, there's a little arrow pointing right, click it, then a big list of crap will show up, like marble, mountain, checker, etc. Click file, then link it to your texture. (I tend to like to use jpgs for textures, though I'm sure it can take quite a few formats.)