Walkthrough for Hogwarts, A History - Guide for Harry Potter and the Chamber of Secrets

Note-I havent played the game in a wile, so I will do my best.

 Follow Hermione's instructions to the restricted section. Once you get there, 
contact Hedwig at the owl podium. Find the owl treats. Give Hedwig the treats
(duh). She will lower a ladder on the right side of the room, next to the door 
covered in ectoplasm.{get rid of it with Skurge later). Of course, climb the 
ladder. Then, jump to the platform above the goopy door. The next thing you do 
is jump to the next bookshelf, AND DON'T JUMP!! If you do, you will not make 
it. To make the jump, lock on to the velvet rope(that is where I got stuck)and 
and cast diffindo on it. Now you con make the jump. Cut the next velvet rope 
too. Then just hop bookshelves until you get the book. I think a door opens. 
Follow the hallways until you meet a living bookshelf! Cast flipendo on it 
until it falls. Get on top of it and follow the platforms. The rest is easy. So 
I won't tell you what to do. Hope I helped!