Authority for mythological source material — Roger T. Macfarlane

“Even Ovid is suspect.” RTM

“The popularity of mythology means that it is treated by innumerable websites; precisely this popularity means that many of these websites are created and maintained by people whose knowledge of the classics, and indeed of mythology, is far from perfect.” Schaps, 327

For studying the Reception of Classical Mythology, these resources are useful essential.

Reid, Jane Davidson. The Oxford Guide to Classical Mythology in the Arts, 1300-1990s. 2 vols. New York: Oxford University Press, 1993.
— Great for reception; starts with authority; cites both classical sources and jumping-off points for scholarly research.

Moog-Grünewald, Maria, ed. The Reception of Myth and Mythology. Brill’s New Pauly, Supplements, 4. Leiden and Boston: Brill, 2010.
— Even stronger for reception, but more densely packed that OGCMA; next stop for researching reception of a myth, after Reid.

Simpson, Michael, trans. and comm. Gods and Heroes of the Greeks: the Library of Apollodorus. Amherst: University of Massachusetts Press, 1976.
— Apollodorus is critically important, but always worth second-guessing; Simpson’s notes help with that.

Grimal, Pierre. Ed. and trans. by S. Kershaw and A.R. Maxwell-Hyslop. The Penguin Dictionary of Classical Mythology. Harmondsworth and New York: Penguin, 1990. — A quick guide worth sticking in your pocket anytime you go to a museum; I turned my copy into an ebook and carry it on my iPad.

Graves, Robert. Introduction by R. Riordan. The Greek Myths. Harmondsworth and New York: Penguin, 2012.
— Quirky, over-the-top erudite, infected by Cambridge ritualism, not nearly as sexy as the Penguin cover (nor Riordan’s endorsement!) would have you believe. (See my Mythmatters critique.)

Lexicon Iconographicum Mythologiae Classicae. 8 vols. in 16 + index & supplements. Zürich: Artemis, c. 1981 -2009. — For reception per se perhaps less valuable; but for teaching that reception will ever be with us, this is da bomb.