U.C. San Francisco has put out the word that anyone who receives an offer to buy books to supposedly benefit the city's Children's Hospital should do what those confronted with books did in Ray Bradbury's Farenheit 411: Call the authorities. Hospital officials have received reports of young men going door to door and selling books for roughly $40 a pop to supposedly benefit UCSF Children's Hospital. Hospital Executive Director Roxanne Fernandes -- who ougtta know -- recently confirmed that she's