Best books for understanding language development

I love learning about how language works.  In particular, I enjoy the all things related to first language acquisition.  It is, quite simply, a real life miracle.  

There are many many great researchers, writers and books.  Some are entertaining, some are informative, and some a combination of both.  I am more interested in learning useful stuff than being entertained, thus I recommend the following.

Language Development by Robert. E. Owens JR.

I read an early article by Owens that I felt summed up much of the research I was reading. He provided a processing model that I found particularly useful. When I left a company (Workbase NZ), a colleague quietly informed me that the staff were getting me a farewell gift - what did I want? 

Of course I jumped at a quite expensive but fantastic book - Language Development: An introduction.

So why is it good?  Well, this book will help you diagnose, understand and address literacy problems.  You will UNDERSTAND what is happening, why, and know what to do.  Powerful.

You will find that you begin to attend to the type, structure and quality of communication in addition to the intended message. It'll become a real treat talking to children because you will notice their language choices and constantly think about cognitive development. You will also notice your learners use of language (written or spoken), and be better able to support them.       

Will it change my life? No
Does it teach hard skills?  To a degree - but mostly lots of applicable theory (theory is good).
Will it help me to help others? YES!!!
Is it fun to read?  Some of it is really fun. For example the Mean Length of Utterance test (MLU) is fun.  However, generally it just really interesting.  For fun, read Stephen Pinker.