a). testing installation and startup
There is a way that is not the perfect one but works: try to access the JMXConsole (http://:/jmx-console).
b). Integrate TomCat/JBoss
You´ll have to copy some jars from %JBOSS_HOME%\client to %TOMCAT_HOME%\common\lib. If you copy all of them, everything will work fine, still some are not necessary.
You´ll have to change the Jetty or Tomcat port (both work on 8080).
There are no docs in JBoss distribution, except some dtds and examples. A good doc is the QuickStart Guide, at http://www.jboss.org/docs/#free-30x.
You can find a lot more information concerning your doubts in this forums, especially in "Beginners Corner".