When you say "biography" I assume you mean the kind printed on paper with ink? I don't know about that, but I do know that his final album "The Man Comes Around" is just as autobiographical as it can get. It's just a stunning album. Have you seen the video of the song "Hurt" from the album - with his wife June Carter Cash, just before she died.
I am amazed at his influence on all forms of music. I saw Coldplay on Austin City Limits a few weeks ago - you know, British rock/pop Coldplay? Lead singer Chris Martin listed Cash as one of his biggest influences.
Did you know that Johnny Cash is the only artist who is a member of the Rock and Roll Hall of Fame,
the Country Music Hall of Fame,
and the Songwriters' Hall of Fame?