You didn't say what you know so far. If you haven't learned Spring yet, "Spring in Action" and the spring online reference are good places to start. You'll need to learn Core Spring before starting with Spring MVC.
If you have learned Spring already, can you ask a more specific question about getting started?
Spring Source Tool Suite IDE is a number of plugins for Spring development pre-bundled into Eclipse. (It also comes with Grails plugins.) You don't need it for Spring development, but it makes things easier - like editing the Spring XML.