I also have a special picture book to recommend. It's Book Fiesta! by children's book author and Dia founder Pat Mora. The full title of the book is Book Fiesta! Celebrate Children's Day / Book Day - Celebremos El dia de los niños / El da de los libros, and this bilingual picture book is indeed a celebration. Rafael López, the illustrator of Book Fiesta! received a Pura Belpré Award for the book's festive illustrations, the 2010 Pura Belpré Illustrator Award. Book Fiesta! is a celebration of the joy of reading for children of all cultures and languages. I think that Book Fiesta! has a much broader appeal than just as a book for Dia. It's a children's picture book that many 3- to 6-year-olds will enjoy any time. It's hard to resist a book that is so joyful.
(Cover art courtesy of HarperCollins)