http://www.gamesas.com/index.php?/topic/955345-wipznifskope-tutorial/
it's probably quite buried but it gives some really good pointers.
Thanks for the link I will look at it asap.
UPDATE: For posterity sake, I found this info in the Niftools forums that deals in texturing:
http://niftools.sourceforge.net/forum/viewtopic.php?f=24&t=1074