How to find out what dependency in Maven to add?

Hello!

I pretty new to Maven.

I wonder if there is an easy way to find out dependecies to add to my pom file.

Suppose that I get a:
java.lang.NoClassDefFoundError: org/dom4j/DocumentException
    at test.hibernate.tools.HibernateUtil.getSessionFactory(HibernateUtil.java:14)

I guess this means that I'm missing some dependency in my pom, correct?

But how do I find out what dependency to add?

I bet there is some easy way to do this.

Best regards
Fredrik