someone told me that the best way to retriee a carolina rig is to cast into deeper waters and retrieve towards the shallow water. is this true? and if the drop off is right next to the shore is it best to simply pull my boat next to the shore and retrieve towrds the shore?  

Let the fish tell you that.

I always try both direction. For instance, this past week the fish were on the outside weed line. After a few hits I relized that they wouldn't hit the bait if I touched the grass. So I turned around and started dragging from deep water and started getting better bites.

I could be completly off base here, but I think you would want to take into consideration whre the fish are/should be.

If they are staging deep and would move up to feed, then I might cast shallow and drag deep.

Whenever I'm in the boat I try both till I figure it out. When I'm stuck on shore there is only one way unless I bring a surf pole ;D ;D ;D