I just found out about The Mixed Media Directory which is the recent creation of Cia Williford.
Here's a short description of the Directory from the site:
"The Mixed Media Art Directory is an all-encompassing directory for links related to mixed media: art and artists, shops and supplies, methods and mediums, blogs and web sites. Please feel free to browse our listings and suggest new ones. Find your favorite artists, or discover new ones! If you care to register, you'll even be able to keep a list of all your favorite links!"
Note: It is suggested that "artists do not add selling sites, i.e. Etsy, ArtFire, eBay, etc. Visitors can find those links on the individual artists' sites."
Cia hopes that the Directory "will grow to be an all-encompassing, one-stop-shop for all things relating to mixed media art."
Check it out - And Good Luck Cia on your new venture.