Maybe I can help contribute by mentioning a book that was mentioned to me:

"The Car Audio Cook Book"

Apparently this book has info on most all aspects of choosing the right components for a car audio install. And it's no rice book either, it's more like a physics text book, citing resonant frequencies and electrical specs. So, though I haven't checked it out yet, I recommend it to you all. It's supposed to be really great.

I'm most interested in getting a speaker setup that's really tweaked and toned for the cabin space of my car. This book is supposed to do help with this.