burzum 'hvis lyset tar oss' and darkthrone 'transilvanian hunger' are always the two i'd recommend to newcomers. i don't believe in going halfway 'cause it never worked that way for me, just throw 'em in at the otherworldly genre-defining deep end, and whilst they're unlikely to get it immediately they'll at least be *fascinated*, and that will eventually spark into something more given time.
I've never really listened to any black metal before, what are good bands to start with? I'm very into death and thrash but haven't got round to exploring this genre before.