One of the big problems with Struts 2 is that it has nowhere near the market penetration that the original Struts has. As a consequence, there is not a whole lot of resources to draw upon when learning. First, bookmark the Struts 2 home page. There's links off that page to download the library and to tutorials. There is only one print book available (AFAIK): Ian Roughley's Practical Apache Struts2. There's a couple of smaller PDF books: Ted Husted's Struts 2 From Square One and Ian Roughley's Starting Struts 2.