top-secret
From 1955 to 1992 CIA ran a "professional magazine: "Studies in Intelligence", a publication created to "support the development of intelligence as a professional discipline".
Maybe they are still publishing it, so it would be more accurate to say that issues from 1955 to 1992 have been declassified, and can be retrieved from the Archives.gov website.

I have started picking some of the most interesting ones, cleaning them up (the sites hosts digital images of low-quality xerox copies or possibly microfilms, also the text-only version is set up as one file per page and nobody seems to have proofread the OCR output) and creating simple PDF documents.

These provide background material for anyone working on an espionage campaign, especially if set in the sixities/seventies, or even just as reading material for people interested in Intelligence Analysis and spycraft.

Maps

Some maps resources

Declassified CIA maps. (Smithsonian)
Russian Cold War maps (Wired)
Other links

Allen Dulles's 73 Rules of Spycraft (PDF) - Some elements of Intelligence work... from www.oss.net