Throughout this book, you have learned a lot about web mapping and GeoServer; however, being an ultimate reference is far outside of this book's scope.
When you are in trouble or simply curious about the new features, there are a lot of online resources that can help you. The project site (http://geoserver.org) contains a lot of information about GeoServer. Besides the basic features, you can find descriptions of the community modules which are plugins developed by the contributors to address specific requirements. Maybe you will find something really useful to you.
The project blog http://blog.geoserver.org announces new releases, ideas, and contributions. Your RSS feed reader can't miss it!
There are two mailing lists, one user-oriented and the other for developers, that are hosted on sourceforge.net. Information and links to the subscription point are...
