MediaNews CEO Dean Singleton, whose company will own the San Jose Mercury News in four weeks, wants to follow in the footsteps of former owner Knight Ridder and Tony Ridder when it comes to philanthropy. According to Sal Pizarro’s column in this morning’s Merc, Singleton’s $20,000 pledge to help sponsor the YWCA’s annual luncheon on Nov. 2 with keynote speaker Mavis Leno, wife of “Tonight Show” host Jay Leno, increased the total raised for the event to $56,000. “MediaNews does believe in community involvement. We believe in giving back,” Singleton said at a KR farewell party with Ridder in attendance.