Step 2: The basic principle
To get a sharp image you will want to fix the camera to something, a decent tripod will get the job done. To avoid differences in focus set the focus manually and keep it set for each animation sequence (you can still adjust it manually as your subject moves / do a focus pull). another thing to try is to move the camera a tiny bit in one direction for each frame, in a straight line or rotationg around your subject, creating the illusion of camera motion.
An added bonus of using a still camera is the amazing image quality you can get even out of the most basic digital camera compared to a consumer video-camera, you could make your end video in full HD resolution.