I'm actually gonna go a step further than Mark and say that all of Steven Pressfield's "Self-Help for Artists" books are basically required reading for anyone who wants to create artwork beyond a hobby level: The War of Art, Turning Pro, and Do The Work. If you like philosophy, the War of Art is a great one. Turning Pro is the most no-nonsense and is what I thing everyone who wants to create anything should read. Do The Work is more of a self-motivational tool when you have a specific project you wanna get done (once I start working on my first EP, I'll be reading it daily).
Ableton's book "Making Music" is another good one, especially for electronic music artists. It's a good color coded reference guide to get you through any particular rut you may find yourself in (though not
every rut).
As far as outside of music production, I recommend reading anything that inspires intellectual curiosity. I'm guessing a lot of us are code/cable monkeys or gearheads or just good old fashioned knob-tweakers. We like figuring stuff out. The more you drive yourself to ask questions and want to figure things out, the more you'll improve in your production. That being said, here are some of the books I've recently read outside of the artistic world:
How Not to Be Wrong: The Power of Mathematical Thinking by Jordan Ellenberg. I personally think that music and math go hand and hand (and engineering and math even moreso), so the more we understand about math the better I think our music can become. This is a great little book on various concepts and ideas. You'll end up with more questions than when you went in, but that's the point, isn't it?
Undeniale: Evolution and the Science of Creation by Bill Nye. I don't have any good reason for you to get into this other than Evolution's gosh darn cool and Bill Nye is the freakin' Science Guy.
