A stop at the public library of the community where your ancestor lived is a must for any family historian. Libraries are a gateway to rich primary source materials on the history and culture of the region they serve, as well as the people who lived in the area. The library is usually the local repository for archived newspapers, city directories, school yearbooks, and other resources specific to the community. Many larger libraries also maintain a local history section, with family histories, community and local history books, photographs, and records such as census enumerations, cemetery transcriptions, and marriage indexes.

Online, a library visit means an excursion to the library's website. Many libraries offer unique online content in the form of digitized original records, or transcribed indexes or databases. The University of Pittsburgh library (http://digital.library.pitt.edu), for example, provides access to historical maps and photos, transcribed census records, and the full text of more than 500 published works that relate to local Pittsburgh and Pennsylvania history. Another unique resource can be found on the website of the New York Public Library (www.nypl.org), where more than 600 Yiskor books (Holocaust memorial books) from the library's collection are available online in digitized format. Even smaller libraries may offer cemetery transcriptions or an index to obituaries that have appeared in their local paper. The Cleveland Public Library (www.cpl.org), which hosts an online Necrology File of cemetery records and newspaper death notices, is one such example. Collaborative databases, in which several libraries or societies pool their records and resources, are also becoming common online. In Indiana, the Vital Information Exchange (VINE) (http://208.119.72.68/vine/vine_home.asp) is a statewide database of vital records, obituaries, newspapers, yearbooks, and other local history resources from Indiana libraries, historical societies, genealogy societies, and related organizations. A group of libraries in central and northeastern Ohio have banded together to create the regional MOLO Obituary Index (www.ohiofamilysearch.org).

Even libraries that don't have online records can be helpful in your research. Most library websites make at least a portion of their catalog available for searching online. Look for a link from the site's home page. You may also find information on submitting lookup or research requests. Many librarians are willing to do brief lookups in indexed books, databases, and clipping files, or provide a copy of an obituary if you can provide a name and date. In some cases this service may cost you a few dollars to cover expenses and postage, but it is well worth it. More and more librarians are also offering online “Ask a Librarian” assistance, either through e-mail or chat.

University and college libraries are sometimes overlooked by genealogists, but they often hold unique historical resources. They can have many unpublished genealogies and histories in their manuscript division, as well as the records of churches and businesses.

One tool used by many genealogists to locate library resources is World-Cat, a catalog of materials held in more than 10,000 libraries worldwide, including public, academic, and state libraries; archives; and historical societies. This includes special collections devoted to local history, which means you may find citations for historical newspapers, oral histories, family histories, cemetery records, historical photographs, family bibles, town or county histories, and a wide variety of other materials. In 2006, WorldCat also opened a free Internet search portal to the public (www.worldcat.org). You can search it directly, and also access it through “find in a library” links for book results in sites such as Google Books and Amazon.