A group of us has been running heroic dungeons on the beta and decided to put together some dungeon guides to give everyone an idea of what to expect. These guides cover both trash and bosses so that you know where you're going, how to get there, and what to do along the way. We'll be posting all eight of them over the next couple weeks and I'll update this post as we finish them.
Edit: Everything's posted! There have been a few bosses that have received some nerfs since we recorded these but the information and strats still apply and work.