I'm implementing GTD for the first time. I wanted to share an observation: As I go through my inbox ("Getting 'in' to empty"), I find a lot of stuff that's actionable, but it's not really the next action; it's more like step 12 of 30. At first, I didn't know what to do with those things. I'm guessing that the value of the next action list is precisely that every thing on there can be done next--that is, it's not dependent on doing something else first.
So where to put those things, I wondered. I realized that these things were really more like project support material.
I'd be interested to hear whether/how others dealt with this in their initial processing of their inbox.