My absolute favorite all-time read and definitely the most influential book for me as a mother. I interviewed Dan Siegel last year (see "Videos with Psychology Rock Stars" under Categories on this page). He is a hero of mine and I was gushing a bit. He is brilliant and has helped marry the fields of psychology and neurology to help us all gain wider wisdom.
Unconditional Parenting by Alfie Kohn
An in-your-face informational and research-based book about the hidden consequences of traditional discipline and absolutely a must-read for every parent wishing not to psychologically scar their children!
Nurture Shock by Po Bronson and Ashley Merryman
Po and Ashley did an excellent job of taking some of the best psychological research that applies to parenting and summing it up here for you.