I recently bought the book "Real Food for Mother and Baby" available here: http://www.amazon.com/Real-Food-Mother-Baby-Fertility/dp/1596913940/ref=sr_1_1?ie=UTF8&s=books&qid=1235507480&sr=8-1
And rated and #1 pregnancy book on Amazon.com
Anyway, Basics I've read so far:
Pregnant women need (real) meat, salt, and fat. It makes sense that to grow another human body you need fat salt and protein.