SPEC Kits are periodically published reports from the Association of Research Libraries (ARL) which "gather information from ARL member institutions on current research library practices and policies. SPEC Kits combine the survey results and documentation from ARL member institutions to guide libraries as they address the ever-changing challenges facing libraries. These guides help libraries learn about current practice in research libraries, implement new practices and technologies, manage change, and improve performance" (http://www.arl.org/resources/pubs/spec/index.shtml).
A full list of SPEC Kits dating back to SPEC Kit 1 (published in October 1973) is available from ARL.
UK Libraries has a subscription through the ARL Digital Publications website, which includes the Kits published during and after 2006. Earlier volumes are available via the HathiTrust Digital Library and are open access. At the HathiTrust site, click on "Collections" and type "SPEC" in the search box.