As a full-time writer (and artist), I use many sources to improve my skills on my path to becoming a better writer. One of my favorite resources is the Writer's Digest magazine, which I receive electronically.
In a recent issue, the focus was on pre-school books, middle grade books, and young adult novels as well. It was perfect timing for me since I was just finishing up my first novel, The House at the Top of the Trees, for middle grade students. So I wrote and told them. I quickly got a response back and they asked if they could publish my email in their magazine. Yes, of course, I said! Well, the September issue not only included my email but also took a quote right out of my email and presented it in bold text! I was thrilled! Especially since every word of my email was true.
If you are a writer looking for help and inspiration with your writing, I highly recommend a subscription to Writer's Digest.