If you have a story you think would make a good children's book and don't know where to begin in terms of writing it or getting it published, the best place to start is with The Society of Children's Book Writers and Illustrators: SCBWI http://www.scbwi.org
Want to learn more about where I earned my M.F.A. in Writing for Children? Check out the Vermont College of Fine Arts: http://www.tui.edu/mfawc
Harold Underdown, a children's book editor, has an informative and helpful site: http://www.underdown.org/
Children's book author Verla Kay's site is chock full of goodies: http://www.verlakay.com/
Yellapalooza is a good site for illustrators.