4 Things you will need
- Spring Recipes by Gary Mak
- Sun's Java Tutorial for your Java brushing up
- Spring reference manual for 2.5.6 (Spring 3 is still in RC1)
- Spring 2.5.6 API docs
You have to buy Spring Recipes but it is a def MUST have, it will help you a lot and the others are free and indispensable. BTW Craig Walls book is quite good as well. You should also download the refcardz for Spring Configuration (also by Craig Walls) and Spring Annotations.