Greek Mythology Sources

The Iliad by Homer - around 8th century B.C.E.

The Odyssey by Homer - around 8th century B.C.E. 

Greek playwrights

Aeschylus: Known for plays like the Oresteia trilogy and Prometheus Bound.
Sophocles: Famous for his tragedies about Oedipus and Antigone.
Euripides: Author of Medea, The Bacchae, and The Trojan Women, among others.

Theogony by Hesiod - around 700 B.C.E. 

Works and Days by Hesiod - around 700 B.C.E.

The Bibliotheca by Apollodorus - 1st or 2nd century  C.E.

Metamorphoses by Ovid - around 8th century C.E.