I seem to remember Paul being un-amused at having words all over the apartment when I did it for Zach, so I mostly confined myself to the school room and Furby's room.
Furby got to put up some of the cards himself, like CLOSET, above. In the week or so since they've been up, I've heard him reading them several times. He struggles with reading, so anything that makes it more fun/interesting is a Very Good Thing in my book. And if Hannah happens to learn something in the process, so much the better.
As I type this, the two of them are sitting behind me, doing a puzzle together. I've recently had Furby start reading her Biscuit books once in a while. Biscuit was a huge favorite of Furby's, and it's so cute to see him share that with her.