Create easily reusable character for still images I am quite new to blender, so excuse me if I am getting some terms wrong (which might be why I didn't find an answer through google..)

I'll start off describing what I want to do, as this will illustrate the problem I am facing: I want to create a series of still images, all featuring the same two characters (but in different positions, of course).

So, ideally, I would not want to re-create the mesh from scratch for each image. I would like to create the character mesh once, and then for each image take the mesh and put it into the right position (like having a doll and moving its arms, legs, general body position, etc.).

I have read about joints, but it seems like this is for games and animations; it might be over the top, as I don't need smooth transitions between positions.

What kind of workflow would you use to easily re-use a character mesh in multiple still images? And if you just alter the original mesh for each image, are there any tricks to prevent it from becoming distorted?

I hope this question makes sense, I am happy to clarify anything that might be unclear...
Well, in fact what you are asking is something easily accomplishable whit the correct rigging technique and enough patience to pose the characters, animation and posing are areas that require patience to get things correctly done, so keep that in mind.

But if your models are simple enough in terms of polygon count, you could easilyuse shape keys to make transitions between poses:
http://www.chocofur.com/using-shape-keys-in-blender.html

Here is a tutorial where you can get started, but remember, nothing is better for posing that rigging.