Using Children's Books to Teach Math

I'm preparing to teach another session on "Linking Math and Literature." If you're up for a little discussion, I'm curious to know your thoughts. Feel free to answer as much or as little as you choose! :)

1. How do you go about choosing children's books to teach math concepts? What, to you, makes a good book for teaching math?

2. How do you use children's books with math?

3. Do you think there are "good ways" and "bad ways" (probably not PC, but you get the point) to use children's books in teaching math?

4. What do you wish you knew about using children's books to teach math?

P.S. I realize my posting has been lax this past week. My work schedule has increased AND I'm taking an on-line class--on math, what else?--so I've been a little lacking in time. But I managed a stop at the used bookstore today to buy another pile of children's books for teaching math! :) Getting excited about this class.