Good. You've made an accurate representation of wood, with an excellent illusion of grain and texture. I'm impressed by your lighting, and everything seems to correctly obey the light source.
I have a small problem with the cracks in the wood: they have no relation to the nails. When you stick something into wood, it splinters around it and with cracks along the grain. There's hardly anything around the nail and screw here.
Another really big thing about this study is there's so little wood here. I mean, it's only the very end of a plank! I think, with this lighting, you should only have a very faint fade to black, that allows more of the side texture to show. You've still made a wonderful wood study, but if there was actually more wood that would help. Great job!