You want to use the JK2 ISAPI connector. Instructions are here.
As far as the JBoss-Tomcat side of things are concerned, you are connecting to the Tomcat AJP13/JK2 connector.
Read http://www.amitysolutions.com.au/documents/JK2-technote.pdf for information on JBoss-Tomcat/Apache connectivity. The same principles apply except you are configuring the web server part differently (ignore the Apache configuration instructions).
IIS -> JK2 ISAPI -> Tomcat JK2 connector -> Tomcat -> JBoss
Hope that helps.