There is a Firefox-LibreOffice extension called “Zotero”.
It is a great tool, i’ve used it while i was writing my thesis. I strongly recommend this tool.
Firefox extension: http://www.zotero.org/support/3.0
LibreOffice/OpenOffice.org integration plugin: http://www.zotero.org/support/word_processor_plugin_installation_for_zotero_2.1
I found this was the easiest to use indeed. Styles are pre-set, which is a plus. The installation of the stand-alone program is unclean however (in fact there is no installation, just a bundle of files and an executable).
I’m a total newbie. How do get the extension for Zotero on Firefox?
Just install browser and LibreOffice plugins or standalone version at http://www.zotero.org/download/
Great hint! Phantastic tool! Was looking for such a tool for years.
When I was writing a paper once I had to insert a very strange looking bibliography. No way to find it in the custom style library from Zotero, so I had to play with the style file by myself. As this is really unhandy, I have looked for a tool to do this job for me and I have found this:
http://editor.citationstyles.org/visualEditor/
There you can play around and create exactly the style you are looking for. Import into Zotero (and many more) is really simple. Great little gadget.
I’ve tried Zotero, and found it to be largely worthless for serious bibliographic work, plus it ties you to the internet (and if you are in areas without access, you’re SOL). Bibus would be your best bet, but there hasn’t been any activity from the maintainer in a long time (it’s very easily configured). If you do a lot of cross-discipline work, Bibus (if it’s ever updated to work with the recent versions of OpenOffice/LibreOffice) is your best bet. Otherwise, I’m looking too.
Also have a look at Mendeley (http://www.mendeley.com/). Like Zotero, it is free, and works with Libreoffice on multiple platforms: Linux, OSX, IOS and Windows. Unlike Zotero (for the time being), it is a standalone program, independent of the browser. And it incudes a pdf viewer and annotator. For me at least, it does a better job of finding and downloading publication details of science journal articles than Zotero, which, I have read, is better for the humanities. So your mileage might depend on your discipline.
It looks brilliant, thanks. I am sure looking into this!
Mendeley may be free (in terms of price) like Zotero, but I believe that it is not FOSS software like Zotero. I’m not sure if that’s a factor that you consider when choosing software, but given that LibreOffice is also FOSS, I thought I should help to clarify for this site.
You can access the Bibliography Database under Tools > Bibliography Database. I’m not sure how to use it, but I’m sure there’s lots of good information in the help files.
I found a screen-cast formatting the bibliography. However there is no info as to how to format a single bibliography entry (you get the short name in brackets by default 
Jabref does a better job of managing references than the built in bibliography system (which works fine just does not help manage all your refs).
There is a plugin for Jabref that lets it push refs into an open LO (or OOo) document.
Setting up the bibliography format in jabref is a little fiddly if you don’t want/can’t use the provided examples but it is not too difficult.
Bibus is also available but I have not used this so can’t comment on it.
Thanks. About Jabref there seems to be a silly limitation which I cannot work with i.e. a single field for author’s first and last name, which doesn’t work in the style I work with 
Bibus doesn’t connect to LO as described in the wiki First connection wizard - Bibus so it’s going to be some more work.
the writer guide http://www.libreoffice.org/get-help/documentation/ chapter 12 has a good section on using the built in bibliography.
Jabref does store the authors name (or names if there are many authors) in one field but, as the first and last name are coma separated, they can be accessed separately in the style definition and used or abbreviated as you want.
You can manage bibliographies very easily in LibreOffice Writer. It has a built-in bibliography database with a few entries preset or you can just insert them into each document on a document by document basis.
Look in Insert → Indexes and Tables → Index and Table… then under type select Bibliography. You can then customise the options quite a lot. You can specify which fields are used for the entries in the Bibliography and in what order for the different types of bibliography entries that are pre-defined.
When you want to add a reference in a document use Insert → Indexes and Tables → Bibliography Entry.