By the way, if you're not an avid reader of this blog and you need help with your characters, I have more than a dozen posts on the subject.
But, if you've read all that and are thirsty for more, here you go!
It's all about the villain, right? I've posted about villains before, but this article was fantastic: Beyond Bastards, Bullies, and Bad Girls breaks down just what an antagonist is, why an antagonist is not necessarily a villain, and how to make their roles pivotal and complex.
Taking it down a notch, here's an article on the basics of Character Development. Maybe you think you need to know more about your character, but are unsure of which questions to ask. This can help.
I've written about this one before and how it helped me, but I gotta share it again. Mary at Kidlit posted on Character-Driven Plots and has a phenomenal list of questions to ask your characters. Seriously. Go. Now.
Do you love your main character? Why? Author Becky Levine shares Why She Loves Her Main Character. I thought this was just so inspiring. This is how I want to feel/write my characters.