{bibliographies} is about creating lists of publications and citing these in a document. If possible, replace this tag with the specific bibliography package you use, e.g. {biblatex} or {natbib}. For questions about specific or customized citation commands, add {citing}. If your question is specifically about BibTeX, use {bibtex}.
Bibliographies are lists of books and other publications like journal articles or web sites. They usually contain references to works which have been cited in a document or which have been used for it in any way.
Bibliographies can be created using \begin{thebibliography} ... \end{thebibliography} or by the command \bibliography together with an external program such as bibtex. In standard LaTeX, the command \bibliographystyle is used to specify a certain way of formating, like numerical, alphabetical, unsorted or author-year style.
Citations are done by \cite or related commands. For questions about specific or customized citation commands, add the citing tag.
There are many packages providing further macros and styles, for instance: natbib, cite and footbib. The most ambitious one, biblatex, is a complete reimplementation of the bibliographic facilities provided by LaTeX. The Bibliography category in the TeX Catalogue lists further packages, styles and tools.
If your question is specifically about BibTeX (e.g. how to modify a style file), use the bibtex tag.
Though it's kind of cross-referencing, please don't use that tag for bibliographies or citations. cross-referencing is intended for in-document cross-referencing by macros such as \label and \ref.
