"Programming Jakarta Struts" is not Struts 2 compatible. There are big differences between Struts 1.x and Struts 2, so this book will not really help you. I heared WebWork is very similar to Struts 2, so "WebWork in Action" could be a interesting book (I never read it). Books with "Struts 2" in the title aren't available (the first will be available on Oct).
The struts2 docu and tutorials should help to solve the biggest starting problems. This was also my way.