Some of the best writing advice I've seen lately is on Cheryl Klein's Blog right here.
Among the articles about writing she has posted is this:
Finding a Publisher and Falling in Love: A Convivial Comparison
Many of her gems of advice are copies of speeches she has made at various writer's conventions.
(Check out the "Picture Book Cookie" one.)
And if you're not sure just who she is -- she was the continuity editor for Harry Potter books, and also edits other books in her job as assistant to Arthur Levine at Scholastic.