This site has a very good selection in women's wide width shoes, and some really good prices. If you look on the right side of the page, there is a "Search by Your Shoe Size" link - this makes finding your size and width a breeze. Definitely worth a look.
For women who need wide shoes Zappos should definitely be one of the first stops, as they have thousands of casual, dress, and athletic shoes in wide widths and extra-wide widths.
Shoes.com has a smaller selection than Zappos, but still a decent amount in "C," "D" and "E" widths.