I would take a double-layer sheet cake and carve a wide "v" in the middle, then angle the two sides (I hope this makes sense....picture an open book and how, when open, the center is lower and the pages fan out at an angle)
I would also use the finest-tooth side of a decorating comb to do the sides....that way it will look like pages.
As for decorating....you can either cut frames, letters/sayings, etc out of fondant and make it actually LOOK like a scrapbook page.....or make various scrapbooking tools (tape, rulers, eyelets, etc)....but I think that actually making it look like a scrapbook page would be the easiest.
I don't know of it is for a birthday or what.....but it might be cute is somewhere on the cake you write something like "All the world's a crop, and we're merely scrappers" or "Crop 'til you drop". If you did a quick search of scrapbooking sites, you could probably find lots of those kinds of sayings.
Good luck! And don't forget to post a picture of your cake!