It's not really a 'how to get better at art' site, but I just found this chick (Senshistock) on Deviant Art who has a huge collection of model poses for artists http://senshistock.deviantart.com/. Lots of dramatic poses too.
Hi! I want to share this youtube channels of these artist that where great inspiration and help to me:
This is the channel of Lisa Clough, she's a wild life/surreal artist, she have great tips for traditional media and for establish an art carrer: www.youtube.com: Lachri Fine Art
This is the channel of Aaron Blaise, a former Disney animator, he was the responsables of creating the Beast (from "The Beauty and the Beast") and the bears from "Brother Bear", he has great tips for character creation, animation, drawing fluidly, creature creaion, etc. I would love to take one of his courses one day www.youtube.com: The Art of Aaron Blaise
This one is the channel of Bobby Chiu, he's an animator and concept artist and has great tips, videos to keep always improving your drawing and interviews with the professionals of the field: www.youtube.com: Bobby Chiu
And this one is the channel of Leilani Joy, she works with acrilics and has more speed paint that tips, but her sparkly personality and optimism is really contagious: www.youtube.com: Leilani Joy