While there are a range of excellent blogs online I've always tended towards physical books for reading and reference. As such here are some of my favorite source materials:
Tabletop Wargames A Designers and Writers Handbook - Rick Priestley and John Lambshead
The handbook is an excellent reference work covering presentation and development of rules for a relatively traditional large scale tabletop war game. Its treatment of skirmish games, or any non-standard unit scale war game, is confined to one quite short chapter but it is written clearly and intelligently by one of the most experienced designers in the field. This book will help you write a war game, particularly if you're writing it largely or totally without experience. However, while it gives excellent advice on how to write a war game it gives very little advice on how to write a good war game, but that might be something you shouldn't expect from any book.
Boardgame Design Advice From The Best In The World - Gabe Barrett
This book actually gives relatively little advice on actual boardgame design, rather it asks the same set of questions repeatedly to many of the top designers working today. Quite a few of the questions are about how a designer gets into the right mindset or their working style, which might be too personal to be of much real help. However, the book offers several useful anecdotal viewpoints and most significantly an accumulation of advice on certain questions. You might question the advice from one designer, its hard to ignore it when its repeated by twenty or so of them.
A Gamut Of Games - Sid Sackson
First written in 1969 and including content going back to 1946 at the very least A Gamut Of Games offers a history lesson for designers and gamers with Sackson's review of the gaming market's leading titles in the late '60s over thirty odd pages being worth the ticket price alone. Incidentally, it seems that if you're looking to make something that will remain popular forty years later deductive games are the way to go. History lesson aside this book contains a number of abstract games created by a Spiel Des Jahres winning master of efficient and effective abstract game design. All the games in the book are designed to be played with easily available components making it a sort of prototype print and play series. A must read for anyone interested in abstract or print and play game design.
A Crowdfunder's Strategy Guide - Jamey Stegmaier
Aimed at extending Stegmaier's boardgame Kickstarter lessons to any form of project, aside from some clear practical advice this book largely sets out Stegmaier's philosophy, which I personally agree with, that greater Kickstarter success can be earned by supporting your own community. Some of the advice is applicable to anyone starting any business, more of it to any community heavy business (such as tabletop gaming) and more again to Kickstarter specific or on-line businesses. Some of the advice is most suitable for a first project aiming for the middle to upper Kickstarter range, but having read it during my second project with the first firmly being aimed at the lower, humble end of the market I still found more than enough useful advice to make it a hugely worthwhile read.
The White Box Essays - Jeremy Holcomb
Combined with The White Box Set, The White Box Essays contain a range of largely stand alone essays best directed at a first time designer intending to pitch to a publisher. However, even coming from a self publishing perspective it has excellent entries on copyrighting and IP protection, box and component design and extended accessibility that I still refer back to now. Even the essays not relevant to your chosen publishing model give an excellent overview of the industry and allow for an educated decision about which method of getting to market is best for you.
Kobold Guide To Board Game Design - Mike Selinker
A series of essays on designing, developing and publishing your first game. I’m mentioning this here mainly because whenever anyone asks about resources this is one of the first books that gets mentioned, and I’m not sure it deserves such whole hearted recommendation. There are a few very good essays that will be useful to everyone but mostly it’s caught between helping you design your niche indie game and sell your latest version of monopoly (one piece of advice actually suggests “Warner Bros. Trivial Pursuit” as a good example of marrying theme to game. I’d suggest that anyone in a position to seriously develop and sell that game isn’t reading a 138-page lightweight softback book on getting their games published). The essay on playtesting is particularly weird, suggesting that the options fall somewhere between dropping $5,000 on a facility and turning up at someone’s house to videotape their family playing your game (I’d strongly suggest neither). Considering the book was published in 2011 it has aged pretty badly, with nothing whatsoever advising on crowdfunding, which is the primary route designers reading such a book are likely to take into the industry. In short, handy as the first thing you pick up, a little dated and with an odd focus throughout. If you’ve done some reading and research otherwise there are likely only one or two essays that you’ll get much out of, though the essay “Finding the Fun” is particularly good.
I'm primarily an abstract thinker and while I have a good handle on themes and visual story telling I lack much of the language needed to communicate to artists. As such I'm always picking up art books to find references. I'm not seeking to study art history though so text heavy art books are of little use. The Taschen series is low cost (about £10 per book), widely available and contains a high proportion of good quality colour plates. By combining art books with sites such as Pinterest using a board shared with your artist even the most visually incoherent designer can get their ideas across.
As a games designer the search for a perfect font will become an ongoing obsession whether you want it to or not. With the internet, type setter catalogues are a dying art but they occasionally pop up in second hand book shops. Any printed material with multiple fonts should be picked up if possible. Fonts read differently on screen as opposed to on printed material so since as a tabletop games designer printed materials are what matter having some to hand can be a big time saver.
Pattern Construction and Reference Books
Fonts and big illustrated artwork aside generating boarder or filler pattern can be its own problem. Also bad filler can totally ruin good artwork. Ancient arts such as Celtic or Viking are a strong source and easily available but none textual graphic design books can be a great source for more modern projects.
Spark Notes/Osprey/Shire Books
Quick mention of vested interest I have worked on Osprey's Gaslands book. Osprey publish a range of short historical reference books, the other two publishers specialise in short reference works in literature and social history respectively. As a designer you should be reading as widely as possible and storing little bits from everything as potential theme or background but going to source texts is not always realistic. As such these sorts of condensed text can be very handy. Once you have established your theme and feel they can offer solid basic research with minimal page counts.
Many unsupported systems can be picked up for very little outlay at second hand or charity bookshops. Whenever you see an old RPG source book or miniatures war games rule book pick them up, if you can spare the shelf space include designer boardgames, and start reading rule books for fun. If you have a favorite game or rule book read it over and over.