Bibliographies (at least in the exact sciences) are similar to cross references. The bibliography contains a list of references at the end of the document, and they can be referenced from within the document. Like section titles, LYX and LATEX make your job easier by automatically numbering the bibliography items and changing citations when the items' numbers change.
Go to the end of the document and switch to the Bibliography environment. Now, each paragraph you type will be a reference. Type The Lyx Tutorial, by the LyX Documentation Team as your first reference. Note that LYX automatically puts a number in a box before each reference. Click on the boxed reference number, and a Bibliography item dialog box appears. You use the first field, the Key, to refer to this reference within the LYX document. By default, it is a number. Change the Key field to ``lyxtutorial'' to make it easy to remember.
Now pick somewhere in your document that you would like to insert
a reference. Do so with Insert
Citation Reference.
A Citation dialog appears. The right panel in this dialog
lists all the bibliography entries, and this field allows you to choose
which bibliography item you want to cite. Select ``lyxtutorial''
(right now, that's the only item in the bibliography), then use the
left arrow in the center to insert it. (You can have multiple citations
in the same place by transferring a number of keys this way.) Now
run LATEX, and you'll see that the citation appears in brackets
in the text, referring to the bibliography at the end of the document.
How are the other fields used? The Text after field in the Citation dialog will put a remark (such as a reference to a page or chapter within the referenced book or article) in the brackets after the reference. If you want the references to have labels instead of numbers in the printed output (for example, some journals would use ``[Smi95]'' to refer to a paper written by Smith in 1995), use the Label field in the Bibliography item dialog. As usual, you can see the User's Guide for details.
Exercise: Fix the bibliography and citation in example_raw.lyx