Setting up my eclipse project using maven (see my last post) wasn't enough to get my project running. I had to also add the jar files as J2EE module dependencies: Project-->Properties-->J2EE Module Dependencies-->Add External Jars. I had to add log4j, commons-logging, and wicket, all from the repository directory that maven created automatically. I'm hoping to find a better way.
Also, I had to ignore the WebContent directory for html because wicket wants the html files to be next to the java sources.