Okay, we have our shelves installed on one side and we're just going to flip the thing over and now we have the back showing so we're going to just attach this side. Again you want to make sure that this corner and this edge are flush. You just have to push it down and hold it in place and drive your screw and we're going to do that all the way down the shelf, driving each screw in. You don't want to push these screws in way to far, just in enough, to where they're flush and they pull the boards together. We're going to screw all these shelves in and I'll show you how to deal with a board that isn't quite straight. As you can see, this board right here, bends a little bit off the line. So to deal with that, we're going to drive a screw, we're going to drive a screw in the top. At the very top edge on the line, like that, drive a screw and then just pull the bookcase off the bench a little bit and push it, just like that with your hand, you'll push it as you're driving another screw. I'm going to push it right up to the line, drive a screw. Now when I get to the bottom, I'm going to have to pull it back a little bit to get the line. So I'm going to pull it back and drive the screw and you basically, that's how you're going to deal with your shelves if they're not quite straight.