If you would like to run WebClient applications under IIS control, there are a few things to be aware of. Normally IIS can not execute Servlets and Java Server Pages (JSPs), so you need to configure IIS to use the JK ISAPI redirector plugin that will let IIS send servlet and JSP requests to Tomcat (and this way, serve them to clients).
Here is a nice guide on how to do it with IIS 7.0 / Windows 2008 Server (other guides available for different versions):
http://www.iisadmin.co.uk/?p=72
There is also information on the Apache site:
http://tomcat.apache.org/connectors-doc/webserver_howto/iis.html
