On my spiritual journey I have read hundreds of books on spirituality, self-development and sustainability. And of all that variety of books I selected just a few, best of the best in my spiritual library, those that combine deep sense of spirituality with practical skills and knowledge: https://ecominded.net/recommended-books - you can order them on Amazon!
Some of these inspiring books (and DVDs) are available for free in pdf format here: https://ecominded.net/books-dvds -please enjoy!