If you want to 'bring back shine' like you stated then the best way to go about it would be to get yourself a DA polisher. If you want further help, let me know, but I'm not going to type out the exact steps if you're not interested in getting one! I'd always recommend claying before using any type of polish, this removes contaminants that will be on the surface which you'll only rub in once you begin polishing. Never had a black car, so can't show you any pictures of how it'd look, however I can tell you that black looks better than any other colour when done properly, here's my grey cars: