Recently, I had the task of symbolising a road reporting map for a local client. To help this client choose appropriate symbololgy to create the look and feel they wanted for the map, I needed a document showing the contents of Esri’s style galleries. After a bit of digging, I found this PDF showing a catalog of the symbols included with the 9.3 release:
It’s an excellent starting point if you need to plan or document symbology at the beginning of a project.
[Note: Even though ArcGIS 10 does not yet have a version of this 9.3 document, many of the symbols are the same. If a version of this document becomes available for ArcGIS 10, we will be sure to post it—so stay tuned!]
For more reading see this link