Below you'll find 'Once Upon A Time in Norway', a 2007 documentary on the 'Inner Circle' of Norwegian Black Metal. It features many interesting interviews with the protagonists of the drama that unfolded in Black Metal's Dream Time. The musicians, now in their mid-thirties, are older, sadder and wiser and distance themselves from the crimes that were committed in the name of Black Metal. The interviews provide extremely valuable insight into the social and psychological processes which drove the Black Metal conspirators to these crimes. The documentary was also brought out on dvd.
Here's a link to an interesting overview of US Black Metal, 'A Blaze in the North American Sky'.