For other activities I also printed out a children's book quiz with the answers from here and the winners got prizes. We wrote silly sayings on diapers to amuse the parents as they change those stinkers too. Simple.
Around the house I decorated with books. I printed out The Keep Calm sign below from Google images (and I felt pretty hip about) and I printed out covers of Golden Book series and created a book banner. I simply whole punched two wholes on each page and strung a ribbon through them. That I hung across our sliding glass doors. I placed books around the house in tables and even in the bathroom.