but this week is of particular note because Concepcion breaks down the Doom of Valyria:

http://grantland.com/hollywood-prospectus/ask-the-maester-the-doom-of-valyria-the-greatest-fighters-in-westeros-and-the-heartbreak-of-greyscale/

Great consolidation of Valyria backstory here, including a ton of stuff I never knew. Column is designed for non book readers looking for deeper info on the show.