Gaping Dragon down first time aswell. Love this Black Knight Sword.
Very large ember acquired, I have no idea where to go now. I think I need to go to the place with the huge metal boar but I'm not sure.
You can go to a few places, hopefully on your travels you ran into a few orange gates that are now down.
If your in Anor you might aswell do that one, near the first bonfire up the steps, you have to fight 2 boars to get into the dark archives.
Go back to firelink at some point, as the worm-dog will tell you the rest of the story.