Know Beans About Meaning

(chiefly US, idiomatic) To know nothing, or almost nothing, about.

Example: 1881, "Notes of the Fine Arts," New York Times, 7 Feb., p. 3 (retrieved 22 Sep. 2009):
  But the great artist doesn't know "beans" about driving oxen. He has put his driver on the "off" side of the yoke.
1963, "Dear Ann Landers," Pittsburgh Post-Gazette, 12 Mar., p. 17 (retrieved 22 Sep. 2009):
  If this self-styled expert in the field of human relations knew beans about handling people he'd get more work out of the women and fewer tears.
2008, Charles Paikert, "Ken Fisher," InvestmentNews, 14 Jul. (retrieved 22 Sep. 2009):
  If wealth managers actually knew beans about anything, they would be in asset management.
1986, "Editorial: The Cabinet Races," Gainesville Sun, 22 Aug., p. 18A (retrieved 22 Sep. 2009):
  His primary opponent, Raphael Herman, is a real estate salesman who frankly admits he knows beans about insurance.