I do not think that there is one answer to this question, but here is mine.
For a simple project without strong modularity requirements, I would use one project.
For the project layout itself, I follow the standard Maven layout . For webapp, this usually means something like this:
.
└── src
├── main
│ ├── java - Application/Library sources
│ ├── resources - Application/Library resources
│ └── webapp - Web application sources
│ └── WEB-INF
└── test
├── java - Test sources
└── resources - Test resources
java :
com.acme.<app>.<module>.web.actioncom.acme.<app>.<module>.web.forms: beanscom.acme.<app>.<module>.service: -.com.acme.<app>.<module>.bo: -com.acme.<app>.<module>.dao: DAOcom.acme.<app>.<module>.dao.hib: Hibernate DAO
<module>.