I love children's books in Spanish and I love that our library has so many of them. We recently checked out a bunch and I plan on making it a habit. I read to my kids all the time in Spanish and it totally reinforces the fact of how important it is to read to your kids, no matter what the language. I also love that I am practicing my Spanish at the same time as reading to my kids. I can often find a word that I never knew.
For example in ¿Cómo estás? by Claudia Bielinsky I learned the word empapado means soaked. I also learned that enfadado means angry or annoyed.
You might also like my post on the gingerbread man in Spanish