Update: I am also having trouble figuring out what the parameters are when using initMap() to make a WMS layer. The wms-bluemarble example gives shows that these are the parameters that are passed:
name, service url, wms version, layers, CRS , format, styles, extra parameters , minZoom, maxZoom
I am having trouble understanding what the name and layer parameters are. Are these taken from the capabilities document provided by the wms layer?