Making Running, Jumping, Attacking (etc) Charset Edits

[evil cabbage 9]

Hey, I'm just wondering, can anyone point me in the direction of some tutorials that teach you how to edit existing charsets. By that, I mean I want to learn how to create things like running, jumping, attacking and isometric versions of various existing charsets (RTP styled). Are there any tutorials on this, or even better, is therre a program that can make these from existing sprites?