The great thing about puppets is, however, you needn't be SUPER ACCURATE with your drawings. That said, the closer you can get to the characters, the better it is for the animation.
I'll be adding this post as questions arise, but hopefully this is good reference for everyone to start out from!
Also, be sure to check out the CHARACTERS SECTION with drawings of a wide array of poses for the characters and little essays on what to think about when posing them and animating them!
Mabel



Mabel is about 3 3/4 heads high. Her body shapes are actually different than the shapes that her clothes make- so be sure to think about this when drawing her. Essentially, pose her body first and THEN draw the clothes on, as the clothes should follow the form of her body and not the other way around.

Also, Mabel's hands are made up of these shapes:

Jonathon

Jonathon is about 1 1/3 heads high. His clothes match his body fairly well, except that the bottom of his coat reaches down a little below where his thigh connects to his pelvis.
Also, these are the shapes of Jonathon's hands:

Height Relationship