Once upon a time, there were few books addressing war gaming. Now there are dozens of titles addressing war game design, its history, business applications, etc. This is not intended to be a comprehensive list, but rather the books below I've read over the course of my gaming career and have found to be particularly useful, to include books on play, critical thinking and visual communication.
Most are available commercially through booksellers such as Amazon; where available, you can click on the image and download a PDF copy. You can also download a complete "War Gaming Bibliography" compiled by Tim Moench here.
And no, I don't get any money for endorsing these books!
War Game Design
These books are specific to the design of professional war games for military, policy, and conflict studies that I routinely turn to for reference.
Game Theory and Play
War games are still games, and I find an appreciation of game theory, design and play mechanics contributes to developing better professional war games.
Analysis and Critical Thinking
Games are all about human players observing, thinking, analyzing and deciding. And yet humans are, for a variety of reasons, notoriously susceptible to sloppy thinking and logic fallacies - inside and outside of games.
Communication and Facilitation
In business and the military it's hard to get away from PowerPoint. In professional games, there is always some sort of briefing at the beginning of a game, typically with PowerPoint, and the game's results are often communicated to senior leadership the same way. And yet most presentations are dreadful! Not that they're just long and boring (ok, that, too), but because of a poor understanding of the principles of visual and oral communications, they fundamentally fail at their task - to effectively communicate.