If ur Application uses database then you have to
create Entity Bean but first u have to decide that
which database u want to use becoz you have to apply
some changes in ur Application server  (JBoss)
according to database actually we have to tell the
datasource to Application server. I think mysql
database is suitable for ur Application, if u don't
have mysql then u can use Access also. First u tell me
about the database u want to use and tell me something
more about ur knowledge in Java means what is ur
comfort level in java programming, Have u worked with
jdbc,rmi etc this will be helpful to me to explain u
more about EJB.