Three books about writing dialogue. I highly recommend the two of them.
Dialogue – The Ultimate Writers' Guide (Kindle version) My rating: ***
Some good points in the book, but it left me with the impression that something was missing. And to be honest, I remember nothing about what I read. So either I'm stupid (and you can stop applauding now) or the author didn't do a good job of teaching the stuff.
I could easily have left out this book from my reading experience.
KD – Instant Dialogue (PDF) My rating: ****
Great report by Rob Howard about how to write dialogue. I recommend that you get this and learn from it.
How to Write Dazzling Dialogue: The Fastest Way to Improve Any Manuscript (Kindle) My rating: *****
This is one of the best books I've EVER read.
The author shows different ways to write and use dialogue, and what's better: It's easy to remember what you've learned after reading it, even if you — like I mostly do — read just before I go to sleep.
Dazzling dialogue! Yes, indeed. You MUST have this book, if it's the only one you ever buy in your life.
(I already had another title from this author, and I immediately bought a third one last night, after I read more of this book. It's excellent, splendid, fantastic, superb, awesome…)