Making Trump, Inc., a podcast about the Trump WH and the Trump Organization, there are a few documents/tools that I find myself using again and again.
Like the transcript from the January 2017 press conference where Sheri Dillon laid out Trump's plan for separating his business from the WH. We keep the audio recording of it at hand, because we often call back to it.
nytimes.com/2017/01/11/us/…
nytimes.com/2017/01/11/us/…
Also, this helpful document that @carlieherman has been keeping up to date. 
factba.se/trump for searching depositions — also a great way to search videos, and video = audio (I assume this is also where people go for their “there’s always a tweet” tweets)
And, not a document, but something I think about a lot is @adamdavidson’s reporting on the Trump Tower Baku and Trump Org due diligence. (This has turned out to be pretty foundational for a lot of Trump, Inc. stories.) newyorker.com/magazine/2017/…
