What you'll need:
Paint (any color you want)
Paint roller for easy application
Mod Podge (an 8oz bottle will be plenty for this size bookcase)
Foam paint brushes
Paper of your choice (I just printed my Disney Lilly print on computer paper and then bought coordinating paper from Michael's)
Obviously the first step is to paint your bookcase. I chose not to prime my bookcase since my paint had primer already mixed in it, however this made me need to do a few coats. I let it dry over night before the next phase of the project.
For the next step, the key is to keep things random. Cut scraps of paper (doesn't even need to be cut straight) and begin placing them where you want them on the bookcase.
Here comes the most time consuming part: Mod Podging every piece in place. I got super caught up in trying to keep it exactly how I had it laid out, and then I realized it was ok to keep everything random and to deviate from the pattern a bit. You really can't mess this up. Just add the Mod Podge to the back of the paper using a foam brush and place on the bookcase keeping it smooth and eliminating any wrinkles. Once all the paper is down, coat the entire surface with a layer of Mod Podge. This will give it a seal.