Okay, this has been what I have been occupying my time with the past day (Well, more like the past hour) But I made a tutorial on how to make an invisible bookshelf, without ruining a book (because I love my books dearly).
So first, I suppose you need supplies.
You need a metal wall brace (The L-shaped metal thing with three holes) Mine happened to be a 5" X 1", but I suppose bigger would be cool too, (it would be stronger that way, but you don't want it to be longer than the width of the book or else you could see where it sticks out of the wall) just make sure the screws fit and can be flush with the metal. (My screws happened to be 12 X 1-1/2, but they might be different for you.) A stud finder (There's always a joke to that) is very handy, you need to make sure you drill through solid wood or it will tear up the wall and probably fall with the weight of the books. You need a drill, and also some velcro (The kind that can peel and stick to things)
AND OF COURSE A BOOK. I chose Pendragon, Amazing series, I still read it (after all these years!) and the author is a really nice guy! Can't go wrong with those books! (But the book you choose doesn't matter, obviously)
Make sure when you choose the drill bit to drill with that it is a little smaller in diameter than the screw. If you hold the screw up behind the bit, you should be able to see the treads on both sides (like in the picture!)
You need a hardcover book (To be the base layer) and if your books are like mine and have covers, and you're like me and like to keep the covers nice (and on the book) you can tape the inside flap of the cover (I've found that the invisible kind doesn't normally tear it up if you want to remove it) to the actual hardcover from the outside. Or you could just use a book with no cover and skip this whole step, haha.
Now that the cover is out of the way (if you ever had that problem) take one of the sticky velcro strips and stick it right in the center of the back cover of the book. Stick another strip to one of the outside sides of the metal brace.
Now, find a stud in the wall and mark it with a pencil (Try to stay towards the center of it because when you level it might require twisting the metal a bit and I was too close to the edge with this one and I only had one screw through the stud, the others went through just the drywall, haha)
Make sure the brace is straight, AND ALSO MAKE SURE THAT THE VELCRO IS ON THE BOTTOM, FACING THE FLOOR. You can kinda see it in the picture, that little white thing under the metal.
When you have it level (or sort of level) mark the holes, drill the top one first (make sure you go straight into the wall to avoid breaking off the bit)
I also found out that putting the top screw in the brace on the wall first before drilling the second hole is a lot easier, it makes it less difficult to keep it level. (But in the picture I had drilled both of the holes, it caused a lot of problems for me because they weren't level even though I tried, it was just harder overall.)
Drill the second hole after re-leveling and put the last screw in.
I found that using just two screws, on the top and bottom holes, works just as well, and it saves on screws. (I only put two on the others bookshelves I made, except on this bookshelf only one screw went through the stud and I put the other through drywall and added the extra, just in case)
You can now set your book (with the back cover hanging down) on the brace. Once you have it on there, look under to match up the velcro on the cover and the brace and mush it together! It should hide the brace and also make the book a little more secure.
Now you can stack them (the books)! It is a bit wobbly sometimes, make sure they are centered to avoid any mishaps. It might be better to have two brackets, but then again, studs aren't all that close to each other which is why (even though the brilliant idea hit me) I didn't attempt it.
TADA! Invisible bookshelf, and no book was harmed! The velcro comes off if you want it to, just pull the tab and the glue deactivates itself. And the book has no trouble closing all the way either, just in case you were wondering!