There are a lot of group author blogs out there, but one that consistently hits it out of the park is YA Outside the Lines. No, I'm not one of the participating bloggers. Some of the participants are my online friends, but frankly that doesn't matter for my recommendation--and some of my favorite posts there have been written by writers I don't even know.
Lauren Bjorkman recently posted on revising to make sure the character wants something, which hit home with me because I've been doing the same thing. Wanting is energy. Indifference is inertia. A character who doesn't want anything has no reason to do anything, and the reader doesn't have much reason to read about her.
Some of my favorite posts from the same site:
R.A. Nelson on Orwell's 1984 from a different point of view: "Julia was spunkier than Winston. More vital and upbeat. Willing to take bigger risks. In spite of everything, she wasn’t a downtrodden character ..."
Barbara Caridad Ferrer on why we need critiques and patience: "The immediate gratification is cool, sure, and God knows, after more than three years of work, I really, really wanted it, but I need an editor. I need an outside eye. I need people to be honest with me. Most of all, I need time."
Sarah Porter on dark and edgy subjects in YA, and why it's vital for someone to write about them: "I felt responsible for preserving a certain moral and emotional realism, and for respecting just how difficult it can be to navigate the darkness of our existence."