This is a question which can be answered by looking into the JavaDoc, so look at this valuable resource and the available Seam documentation first. Furthermore there is a Book Seam in Action which i really advice because it a must-have in addition to the previous resources.
Now for the differnces:
EntityHome is used when you're using JPA and acces the persistency layer with an entityManager The entityHome class provuides a very usefull abstraction layer which gives you direct acces to a single - persisted - object. The Hibernate - version provides the same kind of functionaliy but accesse the Session directly.
On top of these differences you have to be aware that you can use Hiberbnate also with the entityManager, and that you can have another JPA-provider, such as OpenJPA or TopLink, although I strongly advice to start with Hibernate-only, directly or with the entityManager.
Be aware that Hibernate provides a lot vof functionaliy , not provided, well surely not for free by other providers. Additional Collection mappings, Filtering, Text search and Auditing are already available throgh Hibernate.
Go ahead, experiment and don't heistate to ask questions.