You need to add JBoss Tools to your Eclipe installation.
Once you get that installed you can open a HQL Editor and fire your queries.
If you create your Seam project with seam-gen, you should see a file hibernate-console.properties in your root folder. That is the configuration file for JPA/Hibernate
Good luck, post back if you need more help.
Wow! That HQL Editor is really nice. EXACTLY what I was looking for! It does auto-complete and everything, which is a huge help.