A couple more details here.

1. In tomcat's server.xml file in the conf
directory, there will be an entry something
like this:

<!-- Define the default virtual host -->
<Host name="localhost" debug="0" appBase="some-path" unpackWARs="true"
autoDeploy="true">

where "some-path" points to where Tomcat
expects to find the files. Actually,
that path needs a subdirectory ROOT,
and off of ROOT is where your JSP files
need to be.

2. Paths in your URL are case-sensitive, even
if you're running on a Windows system. That
messed me up for a while.