These are links to valuable resources for those who write (and those who want to write) for children.
24 Carrot Writing.com - Writers Kelly Carey, Francine Puckly, Annie Cronin Romano, and Amanda Smith blog about writing for children, setting goals, learning craft, and keeping it real.
Your local library! Yes. Go! Browse the shelves. Talk to your fabulously informed librarians. They know stuff!
SCBWI - Society of Children's Book Writers and Illustrators is an international professional organization for authors and illustrators of books for children and young adults, and provides conferences, workshops, industry advice and networking opportunities.