New document from the Museums, Libraries and Archives Council in the UK:
Guidance on the Management of Controversial Material in Public Libraries
The link to the full document is on this announcement page:
http://www.resourceshelf.com/2009/02/19/uk-guidance-on-the-management-of-controversial-material-in-public-libraries/

The Chartered Institute of Library and Information Professionals [CILIP] has endorsed the document, and has developed a free training course they will deliver in 6 locations: http://www.cilip.org.uk/training/training/controversialstock_CILIPTrainingDevelopmentMLA.htm

ALA has links on its site pertaining to Challenges:
http://www.ala.org/ala/aboutala/offices/oif/statementspols/statementspolicies.cfm#challenges
and workbooks to develop selection policy, as in this example: http://www.ala.org/ala/aboutala/offices/oif/challengesupport/dealing/ALA_print_layout_1_231032_231032.cfm