Latex has several programs/systems to help with the bibliographies in your papers, theses, books, etc. They are all based on BibTeX, which is a system involving a data base of your references that you set up. Since the syntax is rather arcane, there are tools to help with this.
The neatest one is BibWeb, which will go out and search the net (actually MathSciNet) for your references, and format them correctly.
The Bibweb Bibliographic Database Creator
If you have old latex files with bibliographies in them, you can extract them into a bibtex file (if they are in reasonable form)
Create Bibtex (.bib) files from your TeX documents
There are also programs to help with the editing of bibliography files.
Auc-Tex will shorten many commands, find errors for you, and keep track of your files. Its documentation is in the Emacs info system.
Ultra-Tex does a better job of preventing errors, for example, by adding { } and $ always in matching pairs. See: The Ultra-TeX Package for Emacs
It also comes with a Lightning Completion system, which types Latex commands, references, and bibliographic entries faster than you can think. Its documentation is here: Lightning Completion Manual
These three systems are enabled by entries in your emacs setup file.
The CTAN (Comprehensive TeX Archive Network) has everything, if you can find it.
The CTAN Catalog in a readable form.
The TUG (TeX Users Group) has lots of pointers.