ABC News has a good investigative report. Two important details are new to me. First, at the time Palin took office as mayor of Wasilla, conservative Christians in her church were looking into removing two books from the local library: "Pastor, I Am Gay," and "Go Ask Alice." Second, the librarian who told Palin she would not censor books left after two years because Palin made her job too difficult.
Here's the report: