Layers

[GÚÑÑŸ°°G =TAG=.]

Ok I am trying to understand and use the layers in BHD. I know how to name them. I know where to locate them. I don't know how to assign a point at which to make a layer or to "save" a layer. confusing to me. I have been just saving the map with different versions as the map grows. Seems like this is unnessesary.
Anyone know how this well enough to explainit or have a link to a video tutorial?
George