Editing with Google Docs

I am interested in using Google Docs a lot more with my students. I am wondering how you all use it. I can see how we could use it for yearbook, no problem, but it's really newspaper that I can see an issue. I'd like to be able to easily edit their papers using the editing marks. Does anyone have any tips/tricks for this?  I have kicked around the notion of using a drawing app to edit their work with a pen tool and then save it again so they can make the changes. I just don't like changing their papers in the doc because I want them to be able to see what it was and what I suggest that it become. The method that I'm doing right now is printing them, writing on them and then passing them out. The student then gets on the doc and makes the changes. Not bad, but, not all digital either.
In order to make this work, it probably just needs to become the culture of my room. This is difficult for me to establish because it boils down to consistency. It's hard to be consistent when you're feeling the pressure of deadlines. All that tends to go out the window.

Perhaps this guy could use Google Docs for grading as well!