Have you tried to look into this:
http://books.sonatype.com/mvnex-book/reference/multimodule.html
It contains an example that I think can help you to get started i.e. it describes multi module projects. You can then use it as a base reference for your case.
There is some article that describes between Maven 1 and Maven 2 here:
http://community.scmgalaxy.com/blog/view/19418