Scott McCloud wrote a comic book about comic books! The approach isn't so much a "how to" - but a delve into the history and creation. We are taken back to times of cave paintings, brought through to the cuniform in the Kish tablets and into modern art movements vs. writing.
It is a comic dialogue of what comics are, where they came from and what they CAN BE.
His website is a treasure trove for anyone interested in this art form.
Then... THIS happened: