Blogs for picture book writers and illustrators:
And this one: http://www.notesfromtheslushpile.com
If you've written a piece of YA fiction:
Catherine Coe is a freelance editor specialising in consultancy and editing services for writers of children's fiction. Catherine is the founder of All Stories, a mentoring opportunity for underrepresented writers, and was previously senior commissioning editor at Orchard Books and editor at Hodder.
The The Lighthouse Literary, run by editors Sarah Stewart, Senior Editor at Floris Books, and Cat Clarke, author and previously Senior Commissioning Editor, Non-Fiction, at Scholastic.
Or you can get advice from experienced editors Amber Caravéo and Joanna Moult at Skylark Literary, a specialist Children's & YA literary agency and creative consultancy, seeking and supporting the best new voices in children’s fiction.