www.posemaniacs.com

Great reference site for poses, if they don't have the pose you're looking for my friend said that she pieces together the pose she wants, referencing different parts of each picture. So it's good. On the right hand side of the website there's an option for a 30 second drawing thing. Click on it-

It's like quick figure drawing. I've done it in art class, one of us stands on a table, makes some dramatic pose, and we have to draw it in 30 seconds. If you want a real challenge you can set it for 10 seconds and if you really wanna concentrate and try to draw it really well you can have up to 90 seconds. Try it, it's fun and good practice!