Once SiteMesh has been downloaded (or built), configuration is simple.
sitemesh-2.4.1.jar into [web-app]/WEB-INF/lib.[web-app]/WEB-INF/decorators.xml that contains the following:
			<decorators>
</decorators>[web-app]/WEB-INF/sitemesh.xml that contains the following:
<sitemesh>
    <property name="decorators-file" value="/WEB-INF/decorators.xml" />
    <excludes file="${decorators-file}" />
    <page-parsers>
        <parser content-type="text/html"
            class="com.opensymphony.module.sitemesh.parser.HTMLPageParser" />
        <parser content-type="text/html;charset=ISO-8859-1"
            class="com.opensymphony.module.sitemesh.parser.HTMLPageParser" />
    </page-parsers>
    <decorator-mappers>
        <mapper class="com.opensymphony.module.sitemesh.mapper.ConfigDecoratorMapper">
            <param name="config" value="${decorators-file}" />
        </mapper>
    </decorator-mappers>
</sitemesh>
			[web-app]/WEB-INF/web.xml within the <web-app> tag:
<filter>
    <filter-name>sitemesh</filter-name>
    <filter-class>com.opensymphony.sitemesh.webapp.SiteMeshFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>sitemesh</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
		That's it! Your web-app is now setup to use SiteMesh, you can now start building decorators.