To be honest, I don't technically own any writing craft related books. I've pilfered the library shelves and beyond dictionaries and encyclopedias, I've found nothing that helped me personally. Not that they weren't great tools, just not what I was looking for. I learn best by example.
My favorite "writing" books are legion. If I'm working on a paranormal, I surround my desk with two stacks of published paranormals, ones that were great and other's that prompt the thought "How in the heck did that get published?". I've seen great authors wind up in the not so good pile and unknowns end up in the awesome stack. I reread them, pick them apart, look for the why's and how's. I learn from their mistakes. Take note of what puts them in the great pile.