The earliest known writings are the Egyptian Temple Texts, which date to nearly 4,000 B.C.E.  "Hieroglyphics" comes from the Greek "Herios" (God's) and "Glyphos" (inscriptions or writings).  Hieroglyphics are thus literally the writings God gave to humans.  Latter-day Saints have a similar idea in Moses 6:5-6.  The earliest Bible texts are the Nash Papyrus, the Dead Sea Scrolls and the Ketef Himnon amulet, all discussed in more detail in this episode of Martin Tanner's Religion Today Show.