A proper webapp should be self-contained (everything in a single WAR file). That includes the html, images, etc.
Note that Tomcat CAN serve up static content - the front-end Apache is only a performance
boost.
However, for Apache+Tomcat, you direct Apache to the directory you've unpacked the webapp into, and, since it gets first shot at content, it will pick up the static content and serve it directly, but detect servlet and JSP references and pipe them to Tomcat.
Some appservers might not unpack the WAR, or might place them somewhere unpredictable - OR, perhaps, Apache is on a different machine. In this case, you can unpack the WAR into a directory convenient to Apache, excluding the WEB-INF (and META-INF) directories, since they're meaningless to Apache.
[ April 10, 2002: Message edited by: Tim Holloway ]