READ. THE INSTRUCTIONS. CAREFULLY.
Twice I had to re-do an entire section because the instructions wouldn't point out that a small hole had to be facing a certain way.  So make sure you look over the details of every image!  
As for the bookcase itself, I like it, but I have some issues.  The shelves don't sit flush with the wall its up against, so you're going to have gaps where small things can fall behind.  I also with it was taller by another 5-8 inches for another shelf.