You're also supposed to include a current CV for your artist (if contemporary) or create one for an older artist. How?
Living or recently deceased artists: search Google to see if you can find the artist's website easily. Sometimes you can. Often you cannot:
If your artist is deceased or no longer creating, it will be more difficult to find a CV, biography, or press releases but it's not impossible. Well-known artists may have their own museums or galleries.
If you can't find this information using Google, go to Artnet, a free directory of artists and galleries. Search for your artist to see works for sale at galleries, biographies, and press releases. Google the gallery selling the artist's work to find a biography for the artist, or contact a gallery to obtain it. The biography of Kara Walker below can be found at http://www.artnet.com/artists/kara-walker/biography.