Please feel free to add or comment on resources below. 

Databases and lists of books:

• Database of Award-Winning Children's Literature:  A database designed and maintained by Lisa Bartle, a reference librarian at California State University, San Bernardino. It can be searched by a useful list of criteria including genre, age, historical period, gender of protagonist, and setting.
• The American Library Association's Children's Notable Lists
• Association for Library Service to Children booklists
• Young Adult Library Services Association Booklists and Book Awards page
• Newberry Medal and Honor Books, 1922-Present
• Booklists at the Cooperative Children's Book Center at the University of Wisconsin.
• Guys Read: Jon Scieszka's website designed "to help boys find stuff they like to read."
• Weapons of Mass Instruction: Anti-War Books for Young People
• Amelia Bloomer Project  an annotated list of the best "feminist books for young readers" of the year, since 2002.
• ATN Reading Lists:  A wiki developed by librarians to offer reading lists targeted at specific groups (e.g. advanced fifth graders, reluctant readers)
• MotherReader.com's Top Picks for 2006 and Best Books of 2007. 
• Chicken Spaghetti's list of lists of best books of 2008
• http://picturebooksforolderreaders.pbwiki.com/: A wiki developed by Richie Partington's students at the School of Library and Information Science at San Jose State University.  

Discussion groups:

• Child_Lit: A listserv on children's literature.
• CCBC-Net: A listerv "encouraging awareness and discussion of ideas and issues critical to literature for children and young adults. CCBC-Net members explore a wide range of topics in contemporary literature for youth, including multicultural literature, translated books, outstanding, and award-winning books, equity themes and topics, the book arts and book publishing, and more."

Journals:

• Children's Literature
• Children's Literature Association Quarterly

• CM: Canadian Review of Materials:  Offers book reviews, media reviews, news, and author profiles of interest to teachers, librarians, parents and kids. Includes an archived list of reviews searchable by author, title, age, and grade. FormerlyCM: A Reviewing Journal of Canadian Materials for Young People, it was published from 1971 to 1994 by the Canadian Library Association. Under its current title it is published by the University of Manitoba. 
• Children's Lit Book Group at LiteraryMama, "A Literary Magazine for the Maternally Inclined."
• The Edge of the Forest: A children's literature monthly
• School Library Journal: Articles and reviews of books, multimedia, and technology for children and teens.

Organizations:

• Children's Literature Association: An organization dedicated to "encouraging high standards of criticism, scholarship, research, and teaching in children's literature." 
• Children's Book Council: "the nonprofit trade association of publishers and packagers of trade books and related materials for children and young adults." Includes links to various materials, including thematic reading lists.
• The Cooperative Children's Book Center (CCBC): The CCBC is a research library at the School of Education at the University of Wisconsin-Madison. Their website includes many useful resources, including a variety of detailed thematic lists.

Blogs:

• Lessons from the Tortoise: Libby Gruner's blog focused on children's literature.
• MotherReader.com:  A blog on children's and young adult books with the subtitle "The heart of a Mother. The soul of a Reader. The mouth of a smartass."
• American Indians in Children's Literature: Debbie Reese's  blog offering "Critical discussion of American Indians in children's books, the school curriculum, popular culture, and society-at-large."
• Fine Lines: "a sentimental, sometimes-critical, far more wrinkled look at the children's and YA books we loved in our youth."
• Kid*Lit(erary): Laurel Snyder's blog offering "Reviews of some good books you may have forgotten... and some you've never read. (Plus the occasional rant about writing or publishing)."

Other websites:

• The Children's Literature Web Guide
• Children's Books Online: the Rosetta Project
• Association for Library Service to Children(ALSC) Wiki
• surlalunefairytales.com: A website about fairy tales.
• MegaLibrarian:  A wiki collecting and organizing resoures to serve children in a public library

• On 19 July 2007, the New York Times blog asked readers "Who was your Harry Potter?"  and received more than a thousand replies with fond recollections of children's books.  (Some of the posts address the propriety of the New York Times review, which preceded the release of Harry Potter and the Deathly Hallows.)