Digitizing Special Formats
This list of resources has been curated by the Digital Library Federation for the benefit of cultural heritage professionals planning projects involving the digitization of rare and unique materials. Applicants to the Digitizing Hidden Special Collections and Archives  program of the Council on Library and Information Resources  may find these helpful in planning project proposals.
Rather than providing comprehensive coverage, this list includes introductory and reference materials that are good places to begin an exploration of issues of broad import to digitizing cultural heritage materials.
PROJECT PLANNING & MANAGEMENT
The Federal Agencies Digitization Guidelines Initiative (or FADGI)  is a collaboratively maintained clearinghouse of information related to digitization, from project planning , to digital file formats , to technical specifications . FADGI was launched in 2007 under the auspices of the National Digital Information Infrastructure and Preservation Program (NDIIPP). Two working groups of professionals working in federal agencies develop FADGI outcomes: (1) the Still Image Working Group  produces guidelines for creating digital images of cultural heritage materials; and (2) the Audio-Visual Working Group  covers the digitization of analog audio and audiovisual recordings as well as the digital reformatting of born-digital audio or audiovisual content.
The Association of Research Libraries (ARL)  developed the Principles to Guide Vendor/Publisher Relations in Large-Scale Digitization Projects of Special Collections Materials  in 2010 to help institutions build strong working relationships with commercial partners while creating broad access to their collections.
Working with the Digital Library Federation  Assessment Group, Joyce Chapman at the State Library of North Carolina developed the Library Digitization Cost Calculator  using data collected by Duke University, the University of Alabama, and the Triangle Research Libraries Network. The tool helps professionals create rough estimates for still image digitization of archival collections.
Best Practices for TEI in Libraries  provides a recent (2011) overview of possible approaches to incorporating encoded text into large-scale digitization projects.
The "Guidelines and Resources"  page on the National Digital Newspaper Program (NDNP) website  provide detailed and up-to-date information about best practices for digitizing newspapers and making newspaper content broadly accessible and discoverable. The NDNP is a partnership of the National Endowment for the Humanities (NEH) and the Library of Congress. The NEH operates the National Digital Newspaper funding initiative , which offers grants specifically for newspaper digitization.
The Center for Research Libraries (CRL)  maintains the International Coalition on Newspapers (ICON)  database, which contains issue and holdings data for over 170,000 publications dating from the seventeenth century through the present. The ICON project also includes a directory of digitization efforts around the globe .
Rare Books & Manuscripts
The International Federation of Library Associations  (IFLA) Rare Book and Special Collections Section  published its Guidelines for Planning the Digitization of Rare Book and Manuscript Collections  in 2014, covering project design, metadata creation, dissemination, and project assessment.
The International Press Telecommunications Council (IPTC) Core Standard Specification  is a widely used metadata standard for describing photographs and includes details about embedding metadata into digital image files.
Audio and Audiovisual Recordings
The State of Recorded Sound Preservation in the United States: A National Legacy at Risk in the Digital Age [ is a report commissioned by the National Recording Preservation Board  of the Library of Congress that gives an overview of the complex legal and technical issues facing the preservation of recorded sound. The Board itself maintains an Audio Preservation Bibliography .
METADATA AGGREGATION & REGISTRIES
The Digital Public Library of America (DPLA)  aggregates the metadata of digital collections held in educational and cultural heritage institutions across the United States. Institutions with large digital collections may contribute data as Content Hubs, while smaller organizations may contribute through local Service Hubs. Contributors must abide by the DPLA's data policies  in order to participate.
The Print Archives Preservation Registry (PAPR)  collects information about serial titles, print holdings, and archiving terms and conditions. It is a valuable resource for assessing the uniqueness of serial collections and determining the degree of need for digitization of those collections.
The Directory of Open Access Repositories (OpenDOAR)  is an international directory of academic open access repositories.
The Internet Archive  website links to a wealth of relevant information about repositories, copyright and intellectual property, web archiving, and large-scale data storage under "Related Projects and Research" 
The Trustworthy Repositories Audit & Certification: Criteria and Checklist (TRAC)  describes the characteristics of secure and sustainable digital repository management.
The Northeast Document Conservation Center (NEDCC)  has compiled a Digital Preservation Reading List  that provides a thorough introduction to the challenges of digital preservation as they relate to cultural heritage collections. Additional links to resources related to digital preservation are provided on NEDCC's website .
The National Digital Stewardship Alliance (NDSA)  has published the 2015 NDSA National Agenda for Digital Stewardship , which provides a broad overview of current "challenges, opportunities, gaps, and trends" related to building and maintaining digital collections in the United States.
COPYRIGHT & INTELLECTUAL PROPERTY
The "Berkeley Digital Library Copyright Project" produces and disseminates research about copyright issues facing cultural heritage institutions building digital collections. http://www.law.berkeley.edu/librarycopyright.htm
The "Association of Research Libraries" , in particular its initiatives on "Transforming Special Collections in the Digital Age"  and on "Copyright and Intellectual Property" , has published a variety of documents relevant to the digitization of special collections and archives, including a 2012 special issue of "Research Library Issues" that covers legal concerns related to digitizing rare and unique materials. http://publications.arl.org/rli279/1
In 2009, the "Society of American Archivists"  issued "Orphan Works: Statement of Best Practices" to guide decision-making in conducting research into the copyright status of unpublished collections. The document includes a variety of useful links and appendices. http://www2.archivists.org/sites/all/files/OrphanWorks-June2009.pdf
In 2010, "OCLC Research"  organized a seminar and led the effort to develop a description of "Well-intentioned practice for putting digitized collections of unpublished materials online" , which provides useful guidance for institutions developing sustainable copyright risk assessment strategies for their digitization programs. http://www.oclc.org/research/activities/rights.html
In 2013, the "Center for Media & Social Impact"  issued the "Report on Orphan Works Challenges: for libraries, archives, and other memory institutions", a study of the obstacles cultural memory institutions face in their efforts to address concerns about rights and intellectual property that concludes with a set of recommendations for the development and dissemination of best practices for overcoming these obstacles. http://cmsimpact.org/fair-use/related-materials/documents/report-orphan-works-challenges-libraries-archives-and-other-mem
"Copyright and Related Issues Relevant to Digital Preservation and Dissemination of Unpublished Pre-1972 Sound Recordings by Libraries and Archives" describes what libraries and archives can legally do to preserve and make accessible holdings of unpublished sound recordings. http://www.clir.org/pubs/abstract/reports/pub144
The National Endowment for the Humanities (NEH) supports digitization and related activities through the Humanities Collections and Reference Resources program , the National Digital Newspaper Program , and the Preservation and Access Research and Development  grants.
The National Historical Publications & Records Commission (NHPRC)  offers funding for digitization and related activities through the Access to Historical Records program  and the Digital Dissemination of Archival Collections program .