Start with Struts Framework. and make sure you have all your database access code in DAO's exposed by interfaces. Make sure everything working fine with JDBC DAOs. and then slowly include Hibernate stuff ..hibernate.cfg.xml and mappings, HibernateUtil,..and write new implementation of DAOs using Hibernate. This will give you a chance to see how Hibernate eases development over JDBC.
Once you are experienced, you can write Hibernate code directly instead JDBC.