Java Persistence with Hibernate
EJB3 in Action
Seam in Action is - IMO - the only book that covers Seam properly. I have not been very impressed with Yuan's
Seam Framework, 2nd ed- you cannot learn what Seam is about from it and doesn't make people unfamiliar with Seam understand it so they do it properly.
I concur with Adrian, the other books should be about the fundamental technologies underlying Seam. And yes, those two books are very good resources. Yes, Java Persistence with Hibernate is a thick book but it's thick because persistence is a non-trivial topic and you need to go beyond the basics to write a properly-performing enterprise app. What you strive is not only for the developers to know how code something, but to have the discrimination of knowing when to use a certain approach and when not.
For anything that has changed since SiA was published, your team can use the reference docs online.
Seam in Action is the best book ever ! I've read
Practical JBoss Seam Projects,
JBoss Seam, Simplicity and Power beyond Java EEbut it was SiA that has tought me Seam. It explains in great details how things are meant to be done in Seam. Read it and you will thank Dan Allen for his work.
Define Seam beginner. When I started Seam, I only had experience with EJB 2.1. I was a total beginner (including being new to Java 5 with annotations and generics). Seam is an integration framework, which means it touches and does a lot of stuff with JEE 5 APIs.
So listen to me carefully if you are who I was 2.5 years ago.
First thoroughly understand JSF and EJB3. I love Manning books so I recommend JSF in Action and EJB3 in Action.
Then read SiA and the Yuan et al, 2nd ed. These two books are somewhat complementary so I encourage reading both. SiA goes into more depth on some of the same material but the Yuan book seems to cover more topics like Hibernate second level cache.
And of course, always keep JPwH at your side. Great book and even includes an excellent Seam intro chapter (based on Seam 1.x).
Practical Richfaces is recommended as well.
During your Seam training, spend a lot of time understanding (very well!) bijection and conversation scope.
Also, remember that EJB3 is totally optional in Seam apps. A POJO/JavaBean qualifies as a Seam component as well.