An instructional book teaching the medium of pixel art from the ground up, using deeply explanatory language to teach not just how to use various techniques, but also why they work the way they do. Great for beginners and veterans alike, the book contains a plethora of practice exercises as well!
The current version costs $1. Buying through this site is preferred to Amazon, who take a very large cut of the book.
A second edition is in the works, tentatively timed for mid 2017.