We start with a blank White canvas, and we make a selection for a page in the book, like so:
Now we want to distort this to look more like a page out of a book, by curving the middle. Right-click the selection and choose Make Work Path.. Then choose the Pen tool, Add Anchor Point:
Zoom in if you need to and then add an anchor point at the top left, like so:
Now hold Ctrl and drag the anchor up a little, like this:
Now we want to do the same to the bottom, so we have something like this:
Goto the Paths window (Window > Paths) and right-click the Work Path, choose Make Selection. We do not want to Feather Radius (0), click Ok. We should now have a selection of our Path:
Now open up the Layer Styles by either double-clicking the layer or right-clicking it and choosing Blending Options. Choose a Drop Shadow, and reduce the Opacity to 45%, Distance to 3 and Size to 5.
Now right-click this layer and Duplicate it. Adjust the Layer Style of this new layer - make the Drop Shadow Distance 1 and the Size also 1. Now choose the Move tool and hit the Left key twice, and the Up key once. Repeat this process for the number of pages you want. In this example, we have three pages:
Now for the other side. Shift-click all the page layers we just created to select them al (in the Layers window) and then right-click one of them and choose Duplicate Layers. Shift-click all the duplicate layers and then do Edit > Transform > Flip Horizontal, then move them to the other side of the canvas. You will need to modify the Layer styles - edit each one and uncheck the Use Global Light option under Drop Shadow, and change the angle from 120 to 60. You should be left with this:
Now what we want to do is to Ctrl-click the layer of the top page on the left, and Shift-Ctrl-click the layer of the top page on the right, so that we have a selection like this:
Now create a new layer and move it to the top of all the other layers. On this layer, draw a 1px Gray line down the middle of the book. To make it exact, you can choose the Move tool and use the toolbar alignment to align to center:
You may want to Filter > Blur > Gaussian Blur the line slightly (around 0.5px).
Next, create another new layer beneath this one and still with the selection of the two top pages, get a large soft brush of gray and paint down the center like so:
If you need to, you can alter the opacity of either of these layers to get the right blend. Also consider adding a background. You should end up with something like this: