The History of Medusa's Head
Freud: Medusa as anti-phallus
The phallocentric tradition of Medusa neatly explored at the University of Illinois' amazing site for modern and contemporary poetry: Modern American Poetry.
Famous myth-scholar-dudes Joseph Campbell and Robert Graves lead the charge to read the beheading of Medusa as a record of early religious gender politics. Basically, Freud's contribution is that female genitalia are horrifying because to a young boy, his mother's crotch looks like her penis was cut off. Thus the Medusa Head reinforces male castration anxiety, and also all this other stuff that makes my fingers feel angry just typing it. Read it for yourself, please, because I just lost the will to summarize it.
For some short paragraphs discussing the history of Medusa and connecting it to Helene Cixous's "Laugh of the Medusa" you can check out this online portfolio thing. It took me a while to figure out what it was, but it covers a lot of ground quickly.
For me, the most important work I've read on Medusa is Susan Bowers' "Medusa and the Female Gaze," which makes the argument that Freud's reading of the Medusa Head focuses on the genitals in order to shift attention away from Medusa's powerful gaze, which asserts her subjectivity against an insecure male gaze which seeks to objectify her. Bowers reimagines Medusa as a female muse: "Contemporary women artists who embrace Medusa with full awareness of her dark power exhibit a fierce integrity and free expression of female eros."