There are hundreds, maybe thousands, of writing and/or illustrating sites on the web, and many good ones. Here is a sampling to get you started for 2017.
Categories
AE – agents and/or editors
F – fiction
I – illustration
MG – middle grade
O – organizations
PB – picture books
YA – young adult
Agent Query AE
https://www.agentquery.com/
American Library Association O
https://www.ala.org/
Check here for information on awards. They have a section of author and illustrator websites, too.
Art of Storyboarding at Temple of the Seven Golden Camels I
https://sevencamels.blogspot.com
American Booksellers Association/ABC Children’s Group O
https://www.bookweb.org/membership/ABC
Bent on Books AE
https://jennybent.blogspot.com/
Children’s Book Insider
https://cbiclubhouse.com/clubhouse/
Children’s Books
https://childrensbooks.about.com/
Children’s Book Council O
https://www.cbcbooks.org/
Cynsations
https://cynthialeitichsmith.com/cynsations/
DearEditor.com
https://deareditor.com/
Fiction Notes F
http://www.darcypattison.com/
Fiction University F
http://blog.janicehardy.com/
From the Mixed-Up Files… of Middle-Grade Authors MG
http://www.fromthemixedupfiles.com/
Goodreads
https://www.goodreads.com/
Helping Writers Become Authors
https://www.helpingwritersbecomeauthors.com/
The Horn Book
http://www.hbook.com/
InkyGirl
http://inkygirl.com/
Institute of Children’s Literature
https://www.instituteforwriters.com/about/institute-of-childrens-literature/
JacketFlap
http://www.jacketflap.com/
Jane Friedman
https://janefriedman.com/
Kidlit 411
http://www.kidlit411.com/
Literary Rambles
http://www.literaryrambles.com/
Literature and Latte – Scrivener
https://www.literatureandlatte.com/scrivener.php
Manuscript Wish List AE
http://www.manuscriptwishlist.com/
Monster List of Picture Book Agents AE PB
http://frolickingthroughcyberspace.blogspot.com/p/monster-list-of-picture-book-agents.html
Picture Book Month PB
http://picturebookmonth.com/
Publisher’s Marketplace AE
http://www.publishersmarketplace.com/
Resources for Writers – including “Writing for Children’s Magazines” and “Educational Markets for Children’s Writers
http://evelynchristensen.com/writers.html
SCBWI’s Discussion Boards – formerly blue boards
https://www.scbwi.org/discussion-boards
Society of Children’s Book Writers and Illustrators O
www.scbwi.org
The 22 rules of storytelling, according to Pixar F
http://io9.gizmodo.com/5916970/the-22-rules-of-storytelling-according-to-pixar
The Write Conversation
http://thewriteconversation.blogspot.com/
Write for Kids
https://writeforkids.org/
Write to Done
https://writetodone.com/
Writer Beware
http://www.sfwa.org/other-resources/for-authors/writer-beware/
Writer UnBoxed
http://writerunboxed.com/
Writing and Illustrating
https://kathytemean.wordpress.com/
Writing, Illustrating, and Publishing Children’s Books: The Purple Crayon
http://www.underdown.org/
YA Books Central YA
https://www.yabookscentral.com/
If you have others you like, feel free to add in the comments.
