Spring Security. Spring Security - Features. Spring Security: Reference Documentation. 5 Minute Guide to Spring Security. Update!
May 31, 2010: I have published a new book, Spring Security 3, covering many aspects of Spring Security from top to bottom. The book is targeted both at novices and intermediate to advanced users. I’d encourage you to read my blog post of the announcement, and visit the book’s web site, to determine if you think it will help you. Introduction to Spring Security 3/3.1.