Edit: Btw. Don't. Touch. The lineart. ;D Final piece:
LAUGHS BECAUSE AWFUL TUTORIAL.
Really this is an awful tutorial, but basically, for better poses go crazy. Draw weird poses. Once you draw out of control, you can then get it in control. Forget anatomy, we'll fix it later. Look at PHOTO STOCK IMAGES!
It's really helpful. DON'T REFERENCE FROM DRAWINGS!
For one, some people may not like that! And two, you could be learning the artist's mistake!
More quick example sketches for the line of action: [link]
Better tutorials WITH SPONGEBOB!