What do you do on the bookcase part in hogwarts:a history. I'm clueless..

What you do is this:
Whack it backwards with flipendo, and when it's at the end of the track, flipendo it again, and it should collapse. Then you can I think you pull the little boxy-cubie type thing out if the gap and along the track, then hop your way up the pillars, whacking flying books with flipendo as you go, then you get a new spell

Don't build your spell up when firing at the bookcase, instead, fire rapidly at it. You will lose some life when it throws books at you, but if you continuously fire rapidly at it until it falls backwards, it won't take all of your life. You can then go to the bookcases and get more life pasties.
Then face the fallen bookcase, go to the right of the crate, pull it backwards, then let go and move to the left of the crate. Pull it all the way down until it won't go any further, then let go and move to the left of the crate. Then pull it backwards until it stops. It should now be at the back of the first of the middle line of bookcases that have the ghosts flying around them.
Climb onto the the first bookcase. You have to cast a spell at the books to make them move downwards, then you can jump forwards onto the next bookcase. Do this until you get to the end, then jump up onto the balcony and retrieve the spellbook.
While you are jumping over the bookcases, the ghosts will try and get you. Wait until they rear back and scream, then fly towards you. When they do that, press R1 and X and Harry will duck. The ghosts will fly straight over him and won't knock his beans out.
If you are stuck with the next part, let me know.