hi,
is somewhere on internet tutorial how to make realistic shaders?
there are many types in blender (lamber, oren-nayar,toon , fresnel… blin, phong. etc…). i know how to make relatively good material, but i want to make them very good.
i want to know how to do these shaders:
skin, pottery, leather (black leather on sofa), wood, metals (especially really nice dull metal).
if is somewhere more material i´ll be happy 
there are tutorials on anistropic metal shading, wood texture is dependent on the quality of your jpgs (add a little normal to the same texture in black and white on a new texture channel) leather can be simulated with a procedural voronoi noise , clay can be simulated with a little fine-grain noise in your normal mapping, and skin, well, if you can figure that out, tell me. blender doesn’t support “true” subsurface scattering , which is pretty much required, though you can fake it.