One of the most necessary requirements of filming smooth, fluid animation is keeping the camera rock steady. Ideally, find a tripod with solid legs and the ability to tilt, pan, and a head that firmly locks into place. As you begin learning stop motion you will probably keep the camera in one position, but as you develop your skill, you can add zooms, pans, and tilts, for dramatic affect. Though a tripod will save you the headache of having to re-shoot and re-set your scene, they are not entirely necessary. The main thing to remember is that the camera should never move unless you intend it to.