Story - Robert McKee
Ostensibly about screen writing, but essentially dealing with the mechanics of crafting a story. This book was a real eye-opener for me, and taught me that there's a hell of a lot more behind writing than just the words. Essential reading.
Stein on Writing - Sol Stein
You can't really argue with Sol - takes a refreshingly un-wishy-washy approach to the craft, and has the balls to offer hard-and-fast solutions to a lot of writerly problems. Some of the examples are a bit ropey, but there's good, refreshingly direct advice here.
Plot and Structure - James Scott Bell
Good, digestible overview of plot structures - summarises a number of schools of thought, including that dealt with in much more detail by McKee, and provides a useful overview of methods for producing plots, both 'outside in' and 'inside out'.
Characters and Viewpoint - Orson Scott Car
Worth it for the fantastic section on Viewpoint alone - finally brought me to a complete understanding of POV, and the subtleties of omniscience vs limited. The best discussion I've ever seen on the subject.
Becoming a Novelist - John Gardner
John makes writing a religion, and this is a bible. Outlines the characteristics of a writer. I empathised with every word. Read this book, and welcome to the club.
The Art of Fiction - David Lodge
A collection of articles by the venerable Mr Lodge - some of them are simply superb and wonderfully educative, and introduced me to concepts like 'de-familiarisation'. A must read.
The Writer's Journey - Christopher Volger
Uses Joseph Campbell's 'The Hero with a Thousand Faces' to provide a system for crafting hero-quest plots, using the mono-myth outlined by Campbell. If you want a universal story, here's a good place to start. Interestingly applies the idea to a number of hugely successful films.
Self-Editing for Fiction Writers - Rennie Brown and Dave King
The title says it all, and it does exactly what it says. What's particularly useful about this is that it's skewed to fiction writers, and unlike some books on editing I've read, is actually an enjoyable, as well as instructive, read.
Writing a Novel - Nigel Watts
Surprised to find this such a illuminating book due to the fact that it's part of a general 'teach yourself' range, but a very good overview of issues facing writers and good solid advice in all areas.
How Not to Write a Novel - Howard Mittelmark & Sandra Newman
A refreshingly light-hearted approach to the business of writing, but serious advice presented. Easy to read and forget that you're actually learning something in the meantime. The advice is presented in easily digestible chunks so a good one to read 'on the go.' Excellent.