A bibliographer is someone with extensive knowledge about publications in a particular subject. Bibliographers compile lists of books related to the subjects they study, assist libraries with collections, and may also work for private collectors. A career in bibliography generally requires a degree in library science and a degree in the subject the bibliographer is interested in, along with active training in libraries, auction houses, and so forth to learn the rules of the trade.
Many people are familiar with the concept of a bibliography, thanks to being assigned papers with bibliographies while in school. A bibliographer's work is related, although a bit different. Rather than compiling a list of sources used for a paper, a bibliographer attempts to exhaustively list resources related to a subject. For example, someone who specializes in the French Revolution would include a wide variety of texts, from personal journals written by people who were there to the latest academic works on the subject.
Bibliographers can track down and include books, articles, journals, poems, unpublished manuscripts, and even works of art in the bibliographies they generate. It can take years to complete a successful bibliography on a particular subject. During the process, the bibliographer identifies, categorizes, and learns more about a wide variety of texts. The work can include meeting with other bibliographers and book professionals to collect information as well as visiting archive facilities to identify new works which may be relevant.
For a library, a bibliographer can be a very valuable member of the staff. A library which wants to assemble an authoritative collection on a specific subject would hire bibliographers to assist with the task of building and maintaining the collection. A library of Renaissance Studies, for example, would have a bibliographer trained in the period. The bibliographer might also be involved in the arrangements of loans or exchanges of rare books which can be used to improve the quality of the library collections.
Work in this field requires a number of different skills and interests. People should be interested in books and have a specific interest in a particular subject or family of related subjects, ranging from flowers in art to medical history, and they should be skilled at ferreting out and synthesizing information. A bibliographer is also very good at categorizing and describing, and it helps immensely to be multilingual to have access to texts which may not be widely available in the bibliographer's native language.