I was just thinking it would be neat if we had an index of books that have proven helpful to anyone here concerning writing, whether it have to do with writing theory, skeletal structure, worldbuilding, warfare, government, culture...
For instance, right now I could really use some books on combat that are geared toward writers, more specifically a book on swordplay and another on archery. I do not know if such books exist, but if so I'd love to know about them and any similar books that could prove useful to a writer. Is there something like this already? If not, I'd like to start a "bookshelf" for all HWers to add the books that have proven helpful to them (with writing), categorized according to, well, category. (similar to 
this thread for DVD resources) This would give people a place to look before starting a thread (like I have) saying something along the lines of "what are some good books to help with portraying warfare?"
(if there is no noted questionable content, that means only that there is no known questionable content, not that there is none)
Warfare:_____________By the Sword--A History of Gladiators, Musketeers, Samurai, Swashbucklers, and Olympic Champions
Is "a bit mature content wise."Writing Theory_____________The Art of War for WritersYou'll find tactics and strategies for idea generation and development, character building, plotting, drafting, querying and submitting, dealing with rejection, coping with unrealistic expectations, and much more._____________The Elements of StyleHas small sections on different "elements" or "rules" to writing._____________Plot & Structureoffers clear, concise information that will help you create a believable and memorable plot, including:
    •Techniques for crafting strong beginnings, middles, and ends
    •Easy-to-understand plotting diagrams and charts
    •Brainstorming techniques for original plot ideas
    •Thought-provoking exercises at the end of each chapter
    •Story structure models and methods for all genres
    •Tips and tools for correcting common plot problems_____________Plot Vs. Character"Create layered characters by considering personality traits, natural attributes, and backgrounds
•Develop your character's emotional journey and tie it to your plot's inciting incident
•Construct a three-act story structure that can complement and sustain your character arc
•Expose character backstory in a manner that accentuates plot points
•Seamlessly intertwine plot and character to create a compelling page-turner filled with characters to whom readers can't help but relate"_____________Story EngineeringThe vast majority of writers begin the storytelling process with only a partial understanding where to begin. Some labor their entire lives without ever learning that successful stories are as dependent upon good engineering as they are artistry. But the truth is, unless you are master of the form, function and criteria of successful storytelling, sitting down and pounding out a first draft without planning is an ineffective way to begin._____________Wordsmithy(can't vouch for content) "a series of out-of-the-ordinary lessons, each with its own takeaway points and recommended readings...showing how to develop the writer's craft and the kind of life from which good writing comes."_____________The Writer's Journey"explores the powerful relationship between mythology and storytelling in a clear, concise style that's made it required reading for movie executives, screenwriters, playwrights, scholars..." "provides new insights and observations from Vogler's ongoing work on mythology's influence on stories, movies, and man himself."