There is a huge anount of information relating to AWR availablle. We belive the following links are particulary useful.
Department for Business Innovation and Skiils (BIS) guidance May 2011http://www.bis.gov.uk/assets/biscore/employment-matters/docs/a/11-949-agency-workers-regulations-guidance.pdf
ACAS (Advisory, Conciliation and Arbitration Service) Agency Workers and AWR summaryhttp://www.acas.org.uk/index.aspx?articleid=1873
APSCO (Association of Professional Staffing Companies) Agency AWR Impact Assessment Guidehttp://www.apsco.org/Members_services/awr.aspx