The Dresden Codex is an eleven-foot-long Maya manuscript, inscribed on both sides, produced around the beginning of the 13th century. Scholars believe it to be a copy of an earlier book composed between 700 and 900 AD, which would make it the oldest book from the western hemisphere. The contents covers the Maya calendar, mathematics, astronomy, and religious beliefs. See more images from the Dresden Codex and later reproductions at BibliOdyssey. Link
Most of the scholars who would deny its authenticity probably believe the end of the world is coming in 2012, and ancient astronauts actually wrote it.
Thanks! (Archaeologist)