I have just read 'How Babies Talk' by Golinkoff and Hirsh-Pasek.
What an absolutely brilliant book.
It is very scientific in terms of describing what the research tells us about how babies learn language and the process of beginning to talk. But its so easy to read - no obscure references at all.
But not in the least patronising, and although american, very little cheesy, over-the-top stuff.
Ideal for anyone with a baby to read - not in a flash-card-mum sort of way, just out of sheer fascination with their development and wonder at their cleverness.