In his book Difficult Men, Behind the Scenes of a Creative Revolution: From The Sopranos and The Wire to Mad Men and Breaking Bad, author Brett Martin focuses on what went on behind the scenes in some of the greatest dramas of our time: He interviewed showrunners, visited writer's rooms, and offered in-depth analysis into how these shows were made.
For the Breaking Bad section, Martin visited the writer's room during the making of season four, and was able to take a few pictures to display the staff's process and how exactly plots were mapped out ahead of time, before any writing took place. The book is definitely worth a read (or a few reads), but luckily for all of us, Martin provided some of the photos he took to Uproxx. From the fact that the writer's room was in an office for a company called Delphi Information Sciences Corporation to the fact that there's a clay replica of Tortuga's head on a tortoise in the room, these photos are absolutely fascinating.
Also, keep a look out for the storylines that never made it on to the show, like Walt dropping a bloody box into the sea Dexter-style.
You can check out some of the photos above—the rest are over at Uproxx, as well as Dustin Rowles's excellent analysis of the photos, with included excerpts from Martin's book, Difficult Men.