yo, Khengi
sorry, I took longer than I thought.
So, First picture, all you really had to do was move the head forwards and shorten the upper half of his body a bit. It looked like he was kinda falling backwards. It's a tough angle to draw though. I had quite a bit of trouble with it.
To improve on this stuff try to practice drawing cubes and cylinders in perspective.
As for the second picture, I just wasn't really sure what the pose was supposed to be? It looks like an action pose, but I'm not quite sure which direction he's moving. Even though the direction of the hair indicated that he was moving to the left of the picture. His body looked more like it was falling to the right.
Try doing the action yourself before drawing, or think in your head about what the full action would look like. Once you can imagine what the full action would look like in motion, you should be able to more easily draw a single pose from that action.
As for the perspective websites. I don't know of any, but I can teach you if you'd like. What about them would you like to learn? just the basics on how to do it?
Hope I helped a little.