If you want to know how to run Selenium in a Maven webapp project, you can refer to the following post.
Selenium – Integrate the Selenium Tests into Maven Build
If you are a Tapestry user, the pom.xml in the above article may not work as the webapp cannot be started in the Embedded Jetty (404 Not Found). I am not sure the reason behind but i find a work around to solve the problem. The tricky thing is in the Embedded Jetty configuration in the cargo2-maven-plugin.