As for things to read: I'm generally interested in, well, a lot of things, but crypto, security, organizational and national aspects of both, and the like. Schneier's Cryptography and his more recent works (most of which focus increasingly on human factors), comp.risks, The Art of War, Neal Stephenson's Cryptonomicon, random linkage through Wikipedia (highly underrated). Actually, for that last, I should probably write intentional linkage. Find some topic you're interested in, search for a few base articles, and follow the links out to other related aspects. Particularly case studies / people, and the like.
If you're going to study WWII, I have to recommend Daniel Yergin's The Prize (either the book or the video series, I've viewed the latter and confess only skimmed through bits of the former, it's voluminous). The relationship of oil to the events of the 20th century simply cannot be overstated.
Stephenson's acknowledgements also serve as something of an indirect bibliography to some of his sources -- his books in general are fantastically well researched, and often better as learning tools than nominally nonfiction texts (though you do have to keep in mind that they are works of fiction). They're generally much more engaging, for starters (after the first 100-300 pages or so...).
I would recommend the following books:
http://www.amazon.com/dp/0743217349
http://www.amazon.com/dp/006097771X/
http://www.amazon.com/dp/0679762892
http://www.amazon.com/dp/068486780X/
As for being lazy, I'm not about to click through ten [edit six] links on my cell phone just to see what title hides behind the links; I appreciate that parent made a list of (presumably) relevant books -- I would have appreciated it more if he or she listed the actual book titles/authors as well.
As it was; I felt it made sense to recommend Singh's book as it is very good and relevant -- and that it wouldn't contribute much to the discussion to overtly critize parent for being inconveniently (for me) lazy.
But since you bring it up; personally I think it is good netiquette to prefix links with a meaningful title when not contained in the url, when posting in a mostly-plain-text medium. The title and author (optionally year) is relevant information -- an amazon link is trivially discoverable from that (as is a hit in your local library db) -- but the amazon link by itself isn't useful without leaving the context of the discussion. And opening ten tabs on a desktop browser on a reasonable fast connection is certainly not an insourmountable effort -- but is rather inconvenient on a cell phone (For all I know that might be why parent choose to list just the links -- mobile cut'n'paste between tabs is a pretty miserable).
http://www.amazon.com/dp/0743217349 fully expanded is:
http://www.amazon.com/Battle-Wits-Complete-Story-Codebreakin...
e12e's comment was helpful: it supported the original post and included additional information of use to others. And as it happens, Singh's The Code Book was not included in the original list. You can find it here:
http://www.amazon.com/Code-Book-Science-Secrecy-Cryptography...
munin would have performed a superior service (remember: writing is for the benefit of the reader) if he'd at least included descriptive URLs, if not the titles of the works in question.
And your attitude could use considerable improvement.