I have always loved reading children's books - to my children (in English) when they were young, after college when I found a separate Spanish library in town, and now with my students in all different levels.
I consider reading books as the #1 way to build vocabulary and increase fluency. Children's books have several advantages:
- they're interesting
- they have beautiful illustrations
- if students read those books when they were young, it brings back good memories for them
- grammar is not sheltered. Books written for young children have advanced grammar used in context in a compelling way. Exactly what my higher level students need to help move them along.

Yesterday the story contained the word "hilo" (thread) and today's story had "con un hilito de voz" (a small thread of a voz). The students were able to understand the expression today after I asked if they remembered seeing the word in yesterday's story.
Building vocabulary - for sure - and increasing fluency.
I'm a looking forward for March!