I usually do the following to make a B&W from a colour.
I make a white layer on top of the colour photo.
I then go to the HUE overlay on the white layer.
This usually works pretty good and simple as 123.
Of course this does not always work with all photos
but it's a good start I thik.

The above photo was taken from:

http://www.normankoren.com/digital_tonality.html