In your spare moments for reading, I think you will really like this newly published book on child development:

http://www.amazon.com/books/dp/0857027581

Child development is very complicated to understand, but delightful to observe. (I am the father of four children, one now fully grown and living independently.)

This list of books on language development of children, one of your concerns,

http://learninfreedom.org/talking.html

is a bit old, but quite useful for parents.