I think you can give little prods to people. For example, right now you just asked me to help you with the non nice white male authors and I'm gonna get on that.

I think maybe everytime you post a discussion you can ask for volunteers to do this or that. That's how I do it in a slash community I participate in. I post a discussion and then when some poor innocent replies in the comments I answer their comments and give them little prods. I also make the prods part of the discussion.

I always threaten offer them sexual favors, but you can do something else. 8D

You should also think about tags. Maybe that would be a good way to announce to people that they're welcome to post whatever they want, by asking them to use specific tags.

I'll come back soon with some suggestions for the N-NWM list.