I have always loved Stone Soup!! I had a subscription for my classroom when I was teaching and the students loved to see the writing and illustrations of other young writers. Thanks for the link to Noodletools - looks like a great collection of places for kids to publish.
This web-site is a treasure trove of opportunities for young writers. It lists publications and web-sites that accept writing from children.
http://www.fundsforwriters.com/writin...
This e-zine provides contests and publishing opportunities as well as articles for young writers.
http://www.stonesoup.com/stone-soup-c...
If you’re age 13 or younger, you can contribute writing and illustrations to Stone Soup Magazine.