http://www.zerotothree.org/child-development/
The Behavior and Development section of Zero to Three's website contains research-based, parent-friendly information about all domains of early development as well as a Q and A feature and their "Little Kids, Big Questions" podcast series, featuring interviews with experts about issues facing parents of young children. Much of the information applies to children beyond age three.
Frequently updated postings and tip sheets about learning and development, currently including Magazines for Young Children; Transitioning to Kindergarten; Coping with Tragedies. Sign up for a family e-newsletter, if you wish.
http://csefel.vanderbilt.edu/resources/family.html
Brief articles focus on handling common dilemmas at different stages of early social and emotional development, including engaging cooperation, responding to biting, and building self-control and persistence. The Teacher Resource link includes lists of children's books that address social and emotional development themes.