I think you're referring to two seperate processes.
When you're first starting GTD, it's important to gather all the pieces of your life and get them in to your trusted system. You can't spend any time thinking about or doing them them because if you did you'd never complete the sweep.
Once you start processing your inbasket, you have one of a handful of options. Act, delegate, create a Next Action, file, throw away.
You might enjoy the Mastering Workflow chart.