So, let's say the main characters enter a building, a really big laboratory of sorts. They don't know what was being worked on here, because no one is still there, it's been abandoned recently. But for the plot to move on, they need at least a basic grasp of what was studied here, and the reader should get some background as well.
My question is thus: How can I integrate letters of former members/scientists of this Institution or book snippets on the matter as seamless as possible into the story? I envision this could take quite a number and this place is the main stay over the story, so I fear it would be dull that someone just "finds" a piece of writing every chapter or so. I have thought about prefacing each chapter with one of those writings, which would inform the reader without disrupting the story, but would leave the characters in the dark, which is not wanted by me.
Are there best practices for this sort of thing?