i suggest looking into a cheaper solution until you really know what you are doing. then spend a couple hundred bucks on a glidecam.
check out this video, it is a good handle/cage and is super cheap. (two hands on handle=twice as steady)
or this, more like a glidecam. a little more expensive.
this is a fellow NSer's edit made using the steadycam shown in the second video.
Christian Shackleford Mini Edit from Gavin Rudy on Vimeo.