Keeping Confusion out of Collaboration

One of my student project groups is conducting an experiment in creative collaboration. They are crowd-sourcing a novel whose characters are already set up and whose plot is also fixed (divided into chapters and subchapters or "segments"). People sign up to complete a component of the whole.

I'm excited and scared by this idea, and immediately I'm seeing the messiness of collaboration: there are too many ways into the information about the novel and not a clear enough path for the would-be contributors to get to the info that they need:

1. A clear concept of the experiment and what their role in it could be. (The pitch needs to be as clear as the NaNoWriMo concept)
2. A quick, inviting overview of the story and its world (Potential contributors need a quick teaser into the genre, characters, and general plot of the novel -- but without having to read an entire detailed plot summary. Right now, my only choice is to got to a complete chapter outline. That's too much info too soon!)
3. An easy way to sign up for a portion of the project (Something that guides them through a process rather than giving them a lot of links to get lost in.)

Much of this confusion has been fixed through a new wiki. They are getting there! But I still think that the way that they have all their information online shows that they are not keeping straight the three different groups of people for which they are providing resources:

1. administrators (student group members); 
2. prospective authors
3. committed authors

If prospective authors have access to the history of the project, or alternate plots from earlier drafts, they will click themselves into confusion and out of interest. They should not be treated like the project administrators nor like those who are already committed to the project (and who then require more detail and instructions). 

In an effort to help the cause, I have created a prototype invitation for prospective writers -- a series of nine sketches that I put into a Google+ album. What do you think?