These are parenting books I would recommend to a friend:

The Smartest Kids in the World: And How They Got That Way byAmanda Ripley

All Joy and No Fun by Jennifer Senior
The Paradox of Modern Parenthood

Peaceful Parent, Happy Kids by Dr. Laura Markham
How to Stop Yelling and Start Connecting

NurtureShock by Po Bronson
New Thinking About Children

Taking Back Childhood by Nancy Carlsson-Paige
A Proven Roadmap for Raising Confident, Creative, Compassionate Kids

Raising Happiness by Christine Carter
10 Simple Steps for More Joyful Kids and Happier Parents

Becoming the Parent You Want To Be by Laura Davis
A Sourcebook of Strategies for the First Five Years

Mind in the Making by  Ellen Galinsky
The Seven Essential Life Skills Every Child Needs

Baby Hearts by Susan Goodwyn
A Guide to Giving Your Child an Emotional Head Start

Hold On to Your Kids by Gabor Maté
Why Parents Need to Matter More Than Peers

Brain Rules for Baby by John Medina
How to Raise a Smart and Happy Child from Zero to Five

Born to Buy by Juliet B. Schor
The Commercialized Child and the New Consumer Culture

How To Raise An Amazing Child the Montessori Way by Tim Seldin

The Whole-Brain Child by Daniel J. Siegel, M.D. and Tina Payne Bryson, Ph.D.
12 Revolutionary Strategies to Nurture Your Child’s Developing Mind

The Sleepeasy Solution by Jennifer Waldburger and Jill Spivack
The Exhausted Parent’s Guide to Getting Your Child to Sleep from Birth to Age 5