Telling tales - begining to animate

Firstly I printed Ciara's storyboard out and we went over more about what was happening. I added notes and tried to work out better timings and camera angles for my half of the animation, so I clearly understood what I was doing before I started. 

to help me animate I film myself throwing a ball, to get the motion and key frames to get the characters into the right possition.
I can pose the character, however when it comes to animate, I don't know what I'm doing. I've followed the steps, of moving the character into position, setting the frame with the controls still selected and then repeat.

For some reason when I play the scene, it changes from what I set, here I set the arm to a straight out position, when he's just letting go of the ball, but when playing it, his fore arm is tight against his upperarm?

I'm continuously trying to go back over this and fix it, but I get the same result, and it's not how I want it.
Also I cannot render out my scene as it says there's nothing to render?