Click on the title to link to movie tutorial from LightroomNews posted by Martin Evening.
"Do you want to know how to get the best black and white conversions out of Lightroom? This short movie tutorial on Lightroom black and white conversions starts with a few basic tips on how to use the Auto-Adjust Grascale button in conjunction with the White Balance sliders. I then show how to use the target adjustment tool in the Grayscale panel to pick the areas of a photograph that you wish to lighten or darken. Finally, I demonstrate how to desaturate the colors via the HSL panel and achieve a grayscale conversion. The main advantage of using this method is that you can usually achieve smoother looking tones and dark, contrasty skies that are almost completely noise-free."