Which Seam version is used in Seam in Action?
Officially the examples in the book are intended for Seam 2.0.3.GA (which isn't actually released yet, but will be when the book is in print). I cover as many Seam 2.1 features as I could fit in the book, so it is save to say that this book covers Seam 2.1 as well.
Does this book suit for a beginner like me?
The "About this book" answers this question. In that passage, I say that if you are a beginner, you will get enough value out of chapter 1 and 2 to launch you into Seam. seam-gen is a great way for a beginner to start and I cover it in great detail.
Beyond chapter 2, you have to decide if you want to become a Seam master. There is nothing in this book that a dedicated programmer, new or old, will find too hard to learn. I can guarantee that after you read this book, people will be coming to you with questions about Seam. But you have to work for it!
You will also want to pick up the references I encourage you to go read in the book. You could charge per hour what these books cost combined.
Does this book also compare Seam Framework and other application framework such as Spring?
There is a whole chapter on Spring (chapter 15) and I mention it many times throughout the book as I way to compare Seam and Spring.