I read a mailing list called Secrecy News via RSS. One of the things they frequently link to are Congressional Research Service reports. These produce some of the best research out there on various important topics. They are public domain content and are free as in beer. However it’s often easier to find these documents via fee-based services than out on the open web despite web sites like Open CRS. There is a newish report that should be required reading for all librarians: Libraries and the USA PATRIOT Act, originally published in February 2003 now updated for July 2005.