I'd recommend trying to work through the on-line tutorial, then looking for a book.
As far as books, it depends - I liked the APress book "Pro Spring" but felt it was a little scant on Spring MVC coverage, so I also got "Expert Spring MVC and Web Flow". I really didn't like "Beginning Spring 2" though - it isn't really a "Beginner" Spring book. I've heard that Manning's "Spring in Action" is a pretty good beginner book. (But haven't read it personally.) Be sure for all of these books to try and get the newest version - most have an older version and a newer version updated for Spring 2.5
Write once, run anywhere, because there's nowhere to hide! - /. A.C.
I agree with Nathan, there are some very good things in the Pro Spring book, a couple things I don't agree with, and haven't read the MVC/Flow stuff to see how scant it is. Spring in Action is good but unfortunately only covers Spring 2.0, hopefully there will be an updated version.