As the person who produced Cleaning Time, I feel like I can give some good advice based on our experience. Well, I don't know if it's good, but it's definitely advice. Take what you will. Feel free to ignore.
Producer
You have to have a boss. And the boss has to be dedicated to getting the project finished, even if it means kicking people off the project who aren't producing. It's a real drag when 6 months goes by without anything being done because one person is dragging their feet. Plus, the longer things go without anything happening, the more likely other members are to lose interest and become procrastinators themselves. When people sign up to help, it has to be with the understanding that they'll be kicked off if they fail to do their part.
Writing
Don't do it here in this thread. Assemble a writing team with a leader. Someone has to be the head writer, and that person has to organize meetings and delegate responsibilities to the other writers. Allowing individual animators to make creative choices can definitely work, and it's valid, but that makes the project more of a collage of individual shorts and less of a truly cooperative effort towards a solid, single effort.
Animating
Have an animating team with a head animator. Notice a theme? Stylistic choices, such as colors, angles, and part selection can be made by this group to ensure a consistent look and that everyone has the pieces available. Be sure to give each animator a small enough chunk of work to increase the likelihood that they'll complete it and to keep any single animator from dominating the look and feel of the film.
Sound, Voice, and Music
A single person should be all that's needed to coordinate sound. They can find any voice actors that are needed. They can source music, possibly having original material made by capable members of the community. It's definitely enough work to keep someone busy.
Keep the Teams Separate
Other than the producer, no one person should be involved in too many aspects of the project, or else it won't be a community project. If one person does a lot of the animating, sound, and writing, then what you have is that person's project with other people helping. The best way to get a product that is truly an amalgamation of everyone's talent is to erect barriers that prevent an individual's creative influence from dominating.
The idea is to produce a film that feels unlike anything that any of the individuals would be capable of creating themselves. Otherwise we're just looking at a gallery of individual projects or something that looks like what one or two dominant participants could have created themselves.
In addition to a purer creative product, keeping the teams separate and the roles clearly defined forces people to use a skill that you rarely have to use for individual projects, which is communication. The writers must clearly communicate their ideas to each other and to the other teams, while ensuring that they're not loading individuals up with too much work or ignoring others. The animators must clearly communicate with each other, and they must work from someone else's written ideas, rather from what they see in their own minds. These are not muscles we flex often when we are sequestered in our basements working on our own projects. I think it's a fun way to work.
That's all I have to say about that.
