I buy people the book.
I suggest they start out on paper, and direct them to DA's instructions on creating a paper planner.
I
refuse to show them my system, unless they really aren't understanding the concept.
I find GTD to be hindered for people when they are shown what their lists should look like, or what lists they should have, or where they should put their lists. It creates too much overhead, and too much fiddling, and the person is way more concerned with what list app to use, or what color pen, or whether or not they have the right categories than whether or not they are walking through the steps of collect, process, organize, review, and do.
The only GTD Documentation I use, refer to, and/or give out is the
GTD Processing and Organizing diagram. That and the book is all anyone needs to do this.
My list managers have ranged from a notebook, to a Planner Pad, to a moleskine, and now to a combo of iPhone, nook, and PC syncing via Google Tasks and Google Calendar. It's uniquely mine, and no one else probably has the need for exactly the setup I have.