Today is her feast day. Everybody writes about her. Some of them actually know something, like Amy Welborn, which makes less work for me.
There is an enormous amount of legendary material about Mary Magdalene in both West and East. It's fascinating and rich. One of the primary strains in the West has her traveling to Provence (an idea picked up by the radical feminist author of The Woman With the Alabaster Jar, Margaret Starbird, and then turned for her own ends) and, along with Martha and Lazarus, evangelizing the area; there is even some medieval art that depicts Mary preaching and baptizing... [b]ut what we know for sure about her is contained in the Gospels.
Whew, that was easy!